Rechargeable lithium cell having a chemically bonded phthalocyanine compound cathode

ABSTRACT

A rechargeable lithium cell comprising: (a) an anode comprising an anode active material; (b) a cathode comprising a hybrid cathode active material composed of an electrically conductive substrate and a phthalocyanine compound chemically bonded to or immobilized by the conductive substrate, wherein the phthalocyanine compound is in an amount of from 1% to 99% by weight based on the total weight of the conductive substrate and the phthalocyanine compound combined; and (c) electrolyte or a combination of electrolyte and a porous separator, wherein the separator is disposed between the anode and the cathode and the electrolyte is in ionic contact with the anode and the cathode. This secondary cell exhibits a long cycle life, the best cathode specific capacity, and best cell-level specific energy of all rechargeable lithium-ion cells ever reported.

This application claims the benefits of the following two co-pendingapplications: Guorong Chen, Yanbo Wang, Aruna Zhamu, and Bor Z. Jang,“Rechargeable Lithium Cell Having a Phthalocyanine-Based High-CapacityCathode,” U.S. patent application Ser. No. 13/506,778 (May 17, 2012);

Guorong Chen, Yanbo Wang, Aruna Zhamu, and Bor Z. Jang, “RechargeableLithium Cell Having a Meso-Porous Conductive MaterialStructure-Supported Phthalocyanine Compound Cathode,” U.S. patentapplication Ser. No. 13/507,168 (Jun. 11, 2012).

FIELD OF THE INVENTION

This invention relates generally to the field of rechargeable(secondary) lithium metal or lithium-ion batteries and, moreparticularly, to a rechargeable lithium metal or lithium-ion cell havinga phthalocyanine-based high-capacity cathode.

BACKGROUND OF THE INVENTION

Historically, today's most favorite rechargeable energy storagedevices—lithium-ion batteries—actually evolved from rechargeable“lithium metal batteries” using lithium (Li) metal as the anode and a Liintercalation compound as the cathode. Li metal is an ideal anodematerial due to its light weight (the lightest metal), highelectronegativity (−3.04 V vs. the standard hydrogen electrode), andhigh theoretical capacity (3,860 mAh/g). Based on these outstandingproperties, lithium metal batteries were proposed 40 years ago as anideal system for high energy-density applications. During the mid-1980s,several prototypes of rechargeable Li metal batteries were developed. Anotable example was a battery composed of a Li metal anode and amolybdenum sulfide cathode, developed by MOLI Energy, Inc. (Canada).This and several other batteries from different manufacturers wereabandoned due to a series of safety problems caused by sharply uneven Ligrowth (formation of Li dendrites) as the metal was re-plated duringeach subsequent recharge cycle. As the number of cycles increases, thesedendritic or tree-like Li structures could eventually traverse theseparator to reach the cathode, causing internal short-circuiting.

To overcome these safety issues, several alternative approaches wereproposed in which either the electrolyte or the anode was modified. Thefirst approach involved replacing Li metal by graphite (another Liinsertion material) as the anode. The operation of such a batteryinvolves shuttling Li ions between two Li insertion compounds, hence thename “Li-ion battery. Presumably because of the presence of Li in itsionic rather than metallic state, Li-ion batteries are inherently saferthan Li-metal batteries. The second approach entailed replacing theliquid electrolyte by a dry polymer electrolyte, leading to the Li solidpolymer electrolyte (Li-SPE) batteries. However, Li-SPE has seen verylimited applications since it typically requires an operatingtemperature of up to 80° C.

The past two decades have witnessed a continuous improvement in Li-ionbatteries in terms of energy density, rate capability, and safety, andsomehow the significantly higher energy density Li metal batteries havebeen largely overlooked. However, the use of graphite-based anodes inLi-ion batteries has several significant drawbacks: low specificcapacity (theoretical capacity of 372 mAh/g as opposed to 3,860 mAh/gfor Li metal), long Li intercalation time (e.g. low solid-statediffusion coefficients of Li in and out of graphite and inorganic oxideparticles) requiring long recharge times (e.g. 7 hours for electricvehicle batteries), inability to deliver high pulse power (power density<0.5 kW/kg), and necessity to use pre-lithiated cathodes (e.g. lithiumcobalt oxide), thereby limiting the choice of available cathodematerials. Further, these commonly used cathodes have a relatively lowspecific capacity (typically <200 mAh/g). These factors have contributedto the two major shortcomings of today's Li-ion batteries—a low energydensity (typically 150-180 Wh/kg_(cell)) and low power density(typically <0.5 kW/kg).

Although several high-capacity anode active materials have been found(e.g., Si with a theoretical capacity of 4,200 mAh/g), there has been nocorresponding high-capacity cathode material available. To sum it up,battery scientists have been frustrated with the low energy density oflithium-ion cells for over three decades!

In summary, current cathode active materials commonly used in Li-ionbatteries have the following serious drawbacks:

-   -   (1) The practical capacity achievable with current cathode        materials (e.g. lithium iron phosphate and lithium transition        metal oxides) has been limited to the range of 150-250 mAh/g        and, in most cases, less than 200 mAh/g.    -   (2) The production of these cathode active materials normally        has to go through a high-temperature sintering procedure for a        long duration of time, a tedious, energy-intensive, and        difficult-to-control process.    -   (3) The insertion and extraction of lithium in and out of these        commonly used cathodes rely upon extremely slow solid-state        diffusion of Li in solid particles having very low diffusion        coefficients (typically 10⁻⁸ to 10⁻¹⁴ cm²/s), leading to a very        low power density (another long-standing problem of today's        lithium-ion batteries).    -   (4) The current cathode materials are electrically and thermally        insulating, not capable of effectively and efficiently        transporting electrons and heat. The low electrical conductivity        means high internal resistance and the necessity to add a large        amount of conductive additives, effectively reducing the        proportion of electrochemically active material in the cathode        that already has a low capacity. The low thermal conductivity        also implies a higher tendency to undergo thermal runaway, a        major safety issue in lithium battery industry.    -   (5) The most commonly used cathodes, including lithium        transition metal oxides and lithium iron phosphate, contain a        high oxygen content that could assist in accelerating the        thermal runaway and provide oxygen for electrolyte oxidation,        increasing the danger of explosion or fire hazard. This is a        serious problem that has hampered the widespread implementation        of electric vehicles.

For use in a rechargeable lithium metal battery (i.e. a secondarybattery using lithium metal as an anode-active material), thechalcogenide is the most studied cathode-active material. Thechalcogenide is formed of the sulfides, selenides or tellurides oftitanium, zirconium, hafnium, niobium, tantalum, or vanadium. A largelyoverlooked class of cathode active materials is phthalocyanine. Therewas an earlier attempt to use phthalocyanine-based cathode in a lithiummetal battery [J. Yamaki and A. Yamaji, “Phthalocyanine cathodematerials for secondary lithium cells,” Electrochemical Society Journal,vol. 129, January 1982, pp. 5-9; J. Yamaki and A. Yamaji, U.S. Pat. No.4,251,607, Feb. 17, 1981]. In addition to the aforementioned dendriteproblem, these cathodes (both chalcogenide and phthalocyanine) andrelated lithium metal batteries suffer from many major issues:

-   -   (a) These cathode active materials are electrically insulating        and, hence, require the use of a large amount of conductive        additives (e.g. carbon black, CB, or acetylene black, AB) that        are electrochemically inactive materials (not contributing to        lithium storage, yet adding extra weights to the cell). For        instance, in Yamaki et al (1982) cited above, for every 0.1        grams of metal phthalocyanine, 0.1 grams of acetylene were        added. With another 10% by weight of a resin binder, the        proportion of the cathode active material alone (phthalocyanine        itself) in the cathode is less than 50% by weight.        -   By plotting the cathode specific capacity data listed in            Table 1 of Yamaki, et al (1982) we obtained FIG. 1(A), which            indicates that the lithium storing capacity per gram of the            cathode active material only (hydrogen phthalocyanine, H2Pc)            actually decreases with the increasing proportion of the            active material amount (or decreasing acetylene black            proportion). It is very disturbing that at least 50% by wt.            of AB is required. If the weight of acetylene black (AB, a            conductive additive) is accounted for, the cathode specific            capacity is down to unacceptable values of 71.8-345 mAh/g            (of the H2Pc and AB weights combined, not counting the resin            binder weight), as indicated in FIG. 1(B). These are much            lower than what can be achieved with the theoretical            capacity (800-900 mAh/g) of H2Pc.    -   (b) These lithium metal cells exhibit very poor rate capability.        In other words, their lithium storing capacity drops        significantly when a higher charge/discharge rate or higher        current density is imposed on the cells. Table 2 of Yamaki, et        al (1982) indicates that the specific energies of manganese        phthalocyanine (MnPc), iron phthalocyanine (FePc), cobalt        phthalocyanine (CoPc), and nickel phthalocyanine (NiPc) based on        the active material weight alone were 2240, 2300, 1530, and 2220        Wh/kg (of active material weight), respectively, when the        discharge current density was at 1 mA (or 5 mA/g based on the        combined metal Pc/AB weight of 0.2 g). When the discharge        current was increased to 3.14 mA for 0.2 g (or 15.7 mA/g, still        a very low discharge rate), the corresponding specific energies        dropped to 430, 730, 410, and 370 Wh/kg (of active material        weight only), respectively. By dividing these energy density        values by a factor of 5, one obtains the estimated cell-level        energy densities of 86, 146, 82, and 74 Wh/g that are much lower        than those of current lithium-ion cells. These are unacceptably        low for consumer electronics, power tool, renewable energy        storage, and electric vehicle power applications.    -   (c) These cells are not very reversible and typically have very        poor cycling stability and short cycle life. For instance,        according to FIG. 10 of Yamaki, et al (1982), most of the        cathode specific capacity dropped to an unacceptably low vale in        less than 30 cycles (the best was only 100 cycles, for Cu        phthalocyanine).    -   (d) Most of these cathode active materials are slightly soluble        in the liquid electrolyte, gradually losing the amount of        cathode active material available for lithium storage. This is        more severe for phthalocyanine compounds wherein the anions are        highly soluble in commonly used lithium cell electrolytes (e.g.        metal phthalocyanine has high solubility below 1 volt vs.        Li/Li⁺). This is one major reason why the cycling stability of        these cells is so poor.    -   (e) All the metal phthalocyanine compounds (MPc) have a        catalytic effect on decomposition of electrolytes, creating        cycle reversibility and long-term stability issues.

Thus, it is an object of the present invention to provide aphthalocyanine compound-based high-capacity cathode active material(preferably with a specific capacity much greater than 300 mAh/g) foruse in a secondary lithium cell (either lithium metal cell orlithium-ion cell) having a long cycle life.

It is another object of the present invention to provide a rechargeablelithium cell featuring a phthalocyanine compound-based high-capacitycathode active material exhibiting a cathode specific capacity greaterthan 500 mAh/g, typically greater than 1,000 mAh/g, preferably greaterthan 1,500 mAh/g, or even greater than 2,100 mAh/g.

It is still another object of the present invention to provide ahigh-capacity cathode active material (with a specific capacitysignificantly greater than 300 mAh/g, up to 2,200 mAh/g) that can bereadily prepared without going through an energy-intensive sinteringprocess.

Another object of the present invention is to provide a high-capacitycathode active material (with a specific capacity greater than 300 mAh/gor even greater than 2,100 mAh/g) that is amenable to being lithiumintercalation-free or fast lithium intercalation, leading to asignificantly improved power density.

Yet another object of the present invention is to provide ahigh-capacity cathode active material that is electrically and thermallyconductive, enabling high-rate capability and effective heatdissipation.

It is still another object of the present invention to provide ahigh-capacity cathode active material that contains little or no oxygen,reducing or eliminating the potential fire hazard or explosion.

Still another object of the present invention is to provide arechargeable lithium cell that has a long charge-discharge cycle life(>300 cycles, preferably >500 cycles, and most preferably >1,000 cycles)and has a phthalocyanine compound-based high-capacity cathode activematerial that is not significantly soluble in the electrolyte used.

It is an ultimate object of the present invention to provide a highenergy density, rechargeable lithium cell that features a high-capacitycathode active material and exhibits an energy density significantlygreater than the best of existing Li-ion cells.

SUMMARY OF THE INVENTION

The present invention provides a rechargeable lithium cell, includingthe lithium metal secondary cell and the lithium-ion secondary cell thataccomplishes all of the aforementioned objectives. No prior artteaching, alone or in combination with other teachings, has taught,suggested, or anticipated the instant invention.

In one preferred embodiment, the rechargeable lithium cell comprises:

-   -   (a) An anode comprising an anode active material, wherein the        anode active material is a prelithiated lithium storage material        or a combination of a lithium storage material and a lithium ion        source selected from lithium metal, lithium alloy, or        lithium-containing compound;    -   (b) A cathode comprising a hybrid cathode active material        composed of a meso-porous structure of a carbon, graphite,        metal, or conductive polymer and a phthalocyanine compound,        wherein the meso-porous structure is in an amount of from 1% to        99% by weight based on the total weight of the meso-porous        structure and the phthalocyanine compound combined, and wherein        the meso-porous structure has a meso-scale pore with a size from        2 nm to 50 nm to accommodate phthalocyanine compound therein;        and    -   (c) An electrolyte or combined electrolyte/porous separator,        wherein the separator is disposed between the anode and the        cathode and the electrolyte in ionic contact with the anode and        the cathode.

Preferably, the meso-porous structure is in an amount of from 5% to 50%by weight and, more preferably, from 10% to 30% by weight. Thephthalocyanine compound may be advantageously selected from copperphthalocyanine, zinc phthalocyanine, tin phthalocyanine, ironphthalocyanine, lead phthalocyanine, nickel phthalocyanine, vanadylphthalocyanine, fluorochromium phthalocyanine, magnesium phthalocyanine,manganous phthalocyanine, dilithium phthalocyanine, aluminumphthalocyanine chloride, cadmium phthalocyanine, chlorogalliumphthalocyanine, cobalt phthalocyanine, silver phthalocyanine, ametal-free phthalocyanine, a chemical derivative thereof, or acombination thereof.

The meso-porous structure, having a pore size from 2 nm to 50 nm, may bemade from a material selected from graphene, graphene oxide, reducedgraphene oxide, graphene fluoride, doped graphene, functionalizedgraphene, expanded graphite with an inter-graphene spacing greater than0.4 nm, exfoliated graphite or graphite worms, chemically etched orexpanded soft carbon, chemically etched or expanded hard carbon,exfoliated activated carbon, chemically etched or expanded carbon black,chemically etched multi-walled carbon nanotube, nitrogen-doped carbonnanotube, boron-doped carbon nanotube, chemically doped carbon nanotube,ion-implanted carbon nanotube, chemically treated multi-walled carbonnanotube with an inter-graphene planar separation no less than 0.4 nm,chemically expanded carbon nano-fiber, chemically activated carbonnano-tube, chemically treated carbon fiber, chemically activatedgraphite fiber, chemically activated carbonized polymer fiber,chemically treated coke, meso-phase carbon, meso-porous carbon, or acombination thereof. The expanded spacing is preferably greater than 0.5nm and/or the meso-porous structure preferably has a specific surfacearea greater than 100 m²/g.

In particular, the meso-porous structure may be made from a graphenematerial selected from a single-layer sheet or multi-layer platelet ofgraphene, graphene oxide, fluorinated graphene, halogenated graphene,hydrogenated graphene, nitrogenated graphene, pristine graphene, dopedgraphene, boron doped graphene, nitrogen doped graphene, chemicallytreated graphene, reduced graphene oxide, functionalized graphene,functionalized graphene oxide, or a combination thereof, and whereinthis graphene material alone or in combination with at least anothermaterial forms a meso-porous structure having a pore size from 2 nm to50 nm (more preferably in the range of 5 to 10 nm).

In another preferred embodiment, the meso-porous structure is a porous,electrically conductive material selected from metal foam, carbon-coatedmetal foam, graphene-coated metal foam, metal web or screen,carbon-coated metal web or screen, graphene-coated metal web or screen,perforated metal sheet, carbon-coated porous metal sheet,graphene-coated porous metal sheet, metal fiber mat, carbon-coatedmetal-fiber mat, graphene-coated metal-fiber mat, metal nanowire mat,carbon-coated metal nanowire mat, graphene-coated metal nano-wire mat,surface-passivated porous metal, porous conductive polymer film,conductive polymer nano-fiber mat or paper, conductive polymer foam,carbon foam, carbon aerogel, carbon xerox gel, graphene foam, grapheneoxide foam, reduced graphene oxide foam, or a combination thereof.

The meso-porous structure has a specific surface area preferably greaterthan 100 m²/g, more preferably greater than 500 m²/g, and mostpreferably greater than 1,000 m²/g.

The lithium storage material may be selected from: (a) silicon (Si),germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc(Zn), aluminum (Al), titanium (Ti), cobalt (Co), nickel (Ni), manganese(Mn), iron (Fe), cadmium (Cd), or a mixture thereof; (b) alloy orintermetallic compound of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Fe, Co,Ni, Mn, Cd, or a mixture thereof; (c) oxide, carbide, nitride, sulfide,phosphide, selenide, telluride, or antimonide of Si, Ge, Sn, Pb, Sb, Bi,Zn, Al, Fe, Ti, Co, Ni, Mn, Cd, or a mixture or composite thereof, (d)salt or hydroxide of Sn; or (e) a carbon or graphite material.

The phthalocyanine compound may be lodged in a pore or a plurality ofpores of the meso-porous structure to form a hybrid structure having anelectrical conductivity no less than 10⁻² S/cm, preferably greater than1 S/cm.

Preferably, the phthalocyanine compound is lodged in a pore or aplurality of pores of the meso-porous structure and the resulting hybridstructure (phthalocyanine and supporting material combined) preferablyhas a specific surface area greater than 50 m²/g, more preferablygreater than 100 m²/g, and most preferably greater than 200 m²/g. It isadvantageous to have phthalocyanine compound lodging in a pore or aplurality of pores with the phthalocyanine compound forming a thincoating on the pore wall having a coating thickness smaller than 40 nm,more preferably <20 nm, and most preferably <10 nm.

The prelithiated lithium storage material may be selected from: (a) apre-lithiated silicon (Si), germanium (Ge), tin (Sn), lead (Pb),antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti),cobalt (Co), nickel (Ni), manganese (Mn), iron (Fe), cadmium (Cd), or amixture thereof; (b) a pre-lithiated alloy or intermetallic compound ofSi, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Fe, Co, Ni, Mn, Cd, or a mixturethereof; (c) a pre-lithiated oxide, carbide, nitride, sulfide,phosphide, selenide, telluride, or antimonide of Si, Ge, Sn, Pb, Sb, Bi,Zn, Al, Fe, Ti, Co, Ni, Mn, Cd, or a mixture or composite thereof, (d) apre-lithiated salt or hydroxide of Sn; or (e) a pre-lithiated carbon orgraphite material.

The lithium storage material may be selected from graphite worms,exfoliated graphite flakes, expanded graphite, chemically treatedgraphite with an inter-graphene planar separation no less than 0.4 nm,chemically etched or expanded soft carbon, chemically etched or expandedhard carbon, exfoliated activated carbon, chemically etched or expandedcarbon black, chemically expanded multi-walled carbon nano-tube,chemically expanded carbon nano-fiber, or a combination thereof, whereinthis lithium storage material has surface areas to capture and storelithium thereon and has a specific surface area greater than 50 m²/g indirect contact with said electrolyte.

The hybrid cathode active material may further comprise a carbonmaterial coated on or in contact with a particle of the phthalocyaninecompound and wherein the carbon material is selected from carbonizedresin, amorphous carbon, chemical vapor deposition carbon, carbon black,acetylene black, activated carbon, fine expanded graphite particle witha dimension smaller than 100 nm, artificial graphite particle, naturalgraphite particle, or a combination thereof.

The prelithiated lithium storage material may advantageously contain amixture of a high capacity anode material and a high rate capable anodematerial, wherein said high rate capable anode material is selected fromnano-scaled particles or filaments of a lithium transition metal oxide,lithiated Co₃O₄, lithiated Mn₃O₄, lithiated Fe₃O₄, Li₄Ti₅O₁₂, or acombination thereof, and said high capacity anode material is selectedfrom pre-lithiated Si, Ge, Sn, SnO, or a combination thereof. Theprelithiated lithium storage material preferably has a specific capacityof no less than 500 mAh/g based on the anode active material weight,more preferably and typically no less than 1000 mAh/g, and furtherpreferably no less than 2,000 mAh/g.

The electrolyte is preferably organic liquid electrolyte, ionic liquidelectrolyte, polymer electrolyte, gel electrolyte, or a combinationthereof. The electrolyte typically contains a first amount of lithiumions when the cell is made. The electrolyte preferably comprises lithiumsalt-containing liquid electrolyte (e.g. organic liquid or ionic liquid)or gel electrolyte in which lithium ions have a high diffusioncoefficient. Solid electrolyte is normally not desirable, but some thinlayer of solid electrolyte may be used if it exhibits a relatively highdiffusion rate. Lithium-containing ionic liquids are particularlydesired due to their low volatility and non-flammability (hence, low orno fire or explosion hazard).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 (A) The cathode specific capacity data (based on the cathodeactive material weight only) as listed in Table 1 of Yamaki, et al(1982) are plotted as a function of the proportion of the activematerial (=H2Pc/(H2Pc+AB); (B) The same data were re-calculated based onthe H2Pc and AB weights combined, which are more realistic.

FIG. 2 (A) Chemical formula of H2Pc (as an example of metal-freephthalocyanine); (B) Chemical formula of FePc (as an example of metalphthalocyanine); (C) a derivative of FePc-iron (II)octacarboxyphthalocyanine (FeOCPc); and (D) Examples of precursors foruse in the synthesis of various phthalocyanine compounds.

FIG. 3 Schematic of selected procedures for producing pristine graphenesheets, graphite oxide or graphite fluoride (with an expandedinter-graphene spacing), and exfoliated graphite (graphite worms) fromnatural or artificial graphite.

FIG. 4 SEM images of (A) a graphite worm; (B) another graphite wormtaken at a higher magnification; (C) a meso-porous graphitic structureprepared by exfoliating a soft carbon; (D) a meso-porous graphiticstructure prepared by chemically etching or expanding a hard carbonmaterial; (E) an expanded MCMB; (F) expanded carbon fibers; and (G) ameso-porous structure made of graphene sheets re-constituted into anapproximately spherical shape.

FIG. 5 Schematic of selected procedures for producing activateddisordered carbon, oxidized or fluorinated carbon (with an expandedinter-graphene spacing), exfoliated carbon (carbon worms), andactivated/expanded carbon from disordered carbon.

FIG. 6 Schematic of selected procedures for producing activated carbonnanotubes, oxidized or fluorinated CNTs with an expanded inter-graphenespacing, and activated/expanded CNTs from multi-walled CNTs.

FIG. 7 (A) Cathode specific capacity of a series of composite cathodesmade up of 2,11,20,29-Tetra-tert-butyl-2,3-naphthalocyanine (NPc) andacetylene black (AB); (B) Cathode specific capacity of a series ofNPc-graphene hybrid cathodes and a series of NPc-meso-porous A-MCMBhybrid cathodes. Data for the control cell are also presented. Li metalfoil was the anode active material.

FIG. 8 SEM image of a secondary particulate consisting of primaryparticles of naphthalocyanine embraced by and wrapped around by graphenesheets.

FIG. 9 Ragone plot of five types of electrochemical cells: (i) a Li-ioncell using FePc-graphene as a cathode active material and a prelithiatedCo₃O₄ anode active material; (ii) another lithium-ion cell usingFePc-meso-porous graphene structure as a cathode active material and aprelithiated Co₃O₄ anode active material; (iii) a prior art Li-ion cellusing prelithiated Co₃O₄ as the anode active material and LiFePO₄ as thecathode active material; (iv) another prior art Li-ion cell usingnon-prelithiated Co₃O₄ as the anode active material and LiFePO₄ as thecathode active material; and (v) a prior art lithium metal cell using Limetal foil as the anode active material and FePc-AB as the cathodeactive material (50% FePc and 50% AB).

FIG. 10 Ragone plot of four electrochemical cells: (i) a Li-ion cellusing NiPc-RGO as a cathode active material, SnO₂ as an anode activematerial, and Li foil as a lithium ion source; (ii) another lithium-ioncell using NiPc-RGO as a cathode active material and prelithiated SnO₂as an anode active material; (iii) a Li-ion cell using prelithiated SnO₂as the anode active material and NiPc-AC (activated carbon) as a cathodeactive material; and (4) a Li-ion cell using prelithiated SnO₂ as theanode active material and NiPc supported and protected by chemicallyexpanded/exfoliated AC (meso-AC) at the cathode.

FIG. 11 (A) The specific capacity values of a RGO/TSCuPc hybrid cathodematerial and a corresponding cathode material with chemical bonding,obtained from a coin cell configuration with Li metal as the anodeactive material and 1 M LiClO₄ in propylene carbonate (PC) solution asthe electrolyte, are plotted as a function of the charge/dischargecycles. A baseline sample of TSCuPc with 50% by weight of AB as theconductive additive was also prepared in a similar manner (B) Data foran expanded hard carbon (E-HC)/TSCuPc hybrid cathode cell are alsopresented. E-HC has a meso-porous structure prior to TSCuPc bonding.

FIG. 12 Ragone plot of three types of electrochemical cells: two usingMnPc-RGO as the cathode active material and one using MnPc-E-SC(chemically treated soft carbon) cathode, but with three types of anodeactive material: (i) prelithiated Si nanowires, (ii) Li metal foilalone, and (iii) expanded MWCNTs with Li metal foil.

FIG. 13 (A) The specific capacity values of a CoPc-bonded graphenecathode and a corresponding CoPc/graphene hybrid (without bonding) areplotted as a function of charge/discharge cycle number; (B) The specificcapacity values of a CoPc-bonded MCMB cathode (MCMB chemically activatedand porous) and a corresponding CoPc/MCMB hybrid (without bonding) alsoplotted as a function of charge/discharge cycle number.

FIG. 14 The specific capacity values of a hydrogen-bondedFeOCPc/graphene cathode and a corresponding FeOCPc/graphene hybrid(without bonding) are plotted as a function of the charge/dischargecycle number.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention may be more readily understood by reference to thefollowing detailed description of the invention taken in connection withthe accompanying drawing figures, which form a part of this disclosure.It is to be understood that this invention is not limited to thespecific devices, methods, conditions or parameters described and/orshown herein, and that the terminology used herein is for the purpose ofdescribing particular embodiments by way of example only and is notintended to be limiting the claimed invention.

The present invention provides a new and distinct type of rechargeablelithium metal or lithium-ion cell, which exhibits the highest energydensity of all rechargeable lithium-ion batteries ever reported inbattery industry. This new lithium metal or lithium-ion cell features anultra-high capacity cathode having an ability to store lithium ions upto a specific capacity of 2,200 mAh/g, which is 8 times higher than thebest capacity (250 mAh/g) of conventional Li-ion battery cathodematerials. When combined with an anode active material with anultra-high capacity anode (e.g. Li metal or prelithiated silicon), thiscathode enables the lithium-ion cell to store a cell-level energydensity of up to 400-650 Wh/kg, in contrast to the typical 150-200 Wh/kgof conventional Li-ion cells. These experimental values are shocking andcompletely beyond and above the expectations of even the most skilledworkers in the art of electrochemistry or batteries.

The presently invented rechargeable lithium cell (including lithiummetal secondary cell and lithium-ion secondary cell) is preferablycomposed of (a) an anode comprising an anode active material, whereinthe anode active material is a prelithiated lithium storage material ora combination of a lithium storage material and a lithium ion sourceselected from lithium metal, lithium alloy, or lithium-containingcompound; (b) a cathode comprising a hybrid cathode active materialcomposed of a phthalocyanine compound chemically bonded to a conductivesubstrate and, wherein the substrate is in an amount of from 1% to 99%by weight based on the total weight of the substrate and thephthalocyanine compound combined (phthalocyanine compound in the amountof 1% to 99%); and (c) a porous separator disposed between the anode andthe cathode and electrolyte in ionic contact with the anode and thecathode. Preferably, the substrate is in an amount of from 5% to 50% byweight and, more preferably, from 10% to 30% by weight. The substrate ispreferably made from a conductive material, such as carbon, graphite,graphene, carbon nano-tube (CNT), carbon nano-fiber (CNF), carbon fiber,graphite fiber, conductive polymer, and metal.

Preferably, the phthalocyanine compound is chemically bonded to theconductive substrate through a chemical bond selected from covalentbond, ionic bond, π-π interaction, hydrogen bond, coordinate bond, or acombination thereof. The chemical bond can be accompanied by van derWaals forces.

This is essentially a lithium-ion cell if the anode active material is apre-lithiated lithium storage material, such as silicon (Si).Alternatively, the anode is composed of an anode current collector and alithium ion source selected from lithium metal, lithium ion, orlithium-containing compound. The only anode active material is thislithium ion source. This is essentially a type of rechargeable lithiummetal cell.

It is important to state from the outset that the meso-porous structurehaving a pore size of 2-50 nm (most preferably 5-10 nm) is not anarbitrarily selected pore size range. This is selected based on ourexperimental observations (after an extensive and in-depth study)summarized below:

-   -   (1) It was difficult to impregnate a phthalocyanine compound        into pores of a conductive structure if the pore size is less        than 2 nm in size. It was practically impossible to impregnate a        pore smaller than 1 nm.    -   (2) There has been little or no dissolution of a phthalocyanine        compound in the liquid electrolyte used in the rechargeable cell        if most of the pore sizes are in the range of 2-50 nm and there        has been no dissolution or weight loss of a phthalocyanine        compound If the pore size is less than 10 nm. This leads to        minimal capacity decay of the cell upon repeated        charges/discharges for a large number of cycles.    -   (3) It is most easy to impregnate pores larger than 5 nm.    -   (4) It is undesirable to have too many pores larger than 100 nm        because these large pore sizes imply a lower cathode tap density        (lower amount of cathode active material packed into a unit        volume of the cathode material). A pore size of <50 nm is        preferred and <20 nm is further preferred.

The phthalocyanine compound may be selected from a metal phthalocyaninecompound (such as copper phthalocyanine, zinc phthalocyanine, tinphthalocyanine, iron phthalocyanine, lead phthalocyanine, nickelphthalocyanine, vanadyl phthalocyanine, fluorochromium phthalocyanine,magnesium phthalocyanine, manganous phthalocyanine, dilithiumphthalocyanine, aluminum phthalocyanine chloride, cadmiumphthalocyanine, chlorogallium phthalocyanine, cobalt phthalocyanine, orsilver phthalocyanine), or a metal-free phthalocyanine (e.g. hydrogenphthalocyanine), a chemical derivative of a metal or metal-freephthalocyanine, or a combination thereof. This group of material has adistinct characteristic that it is a planar, aromatic molecule that hasa high theoretical lithium storage capacity, but extremely lowelectrical and thermal conductivities. Several examples are given inFIGS. 2(A), 2(B), and 2(C).

Most of these phthalocyanine compounds are commercially available.However, some phthalocyanine compounds containing functional groupscapable of forming a chemical bond with a conductive substrate (e.g.graphene oxide or functionalized graphene) can be readily synthesized.In particular, functionalized phthalocyanine can be produced by heatingphthalic acid derivatives that contain nitrogen functional groups. Goodexamples of precursors are phthalonitrile and diiminoisoindole. Forinstance, a useful route to produce H2Pc is to heat phthalanhydride inthe presence of urea. However, these reactions are more efficient in thepresence of metal salts. Other precursors include o-cyanobenzamide andphthalimide. Several of these starting materials are shown in the FIG.2(D).

For use in the presently invented cell, transition metal phthalocyaninecompounds, such as iron phthalocyanine (FePc), nickel phthalocyanine(NiPc), manganous phthalocyanine (MnPc), and cobalt phthalocyanine, areparticularly desirable due to their high lithium storage capacities andthe high cell voltages when they pair up with selected anode activematerials. They are also found to be chemically compatible with a widearray of conductive materials, such as carbon, graphite, conductivepolymer, and carbon/graphite-coated metal.

The following types of porous structures are found to be particularlysuitable for use to support and protect the phthalocyanine compound: aporous sheet, paper, web, film, fabric, non-woven, mat, aggregate, orfoam of a carbon or graphite material that has been expanded, activated,chemically treated, exfoliated, and/or isolated (isolation means thegraphene planes that constitute a carbon crystal have been separated andisolated from one another to form graphene sheets). This porousstructure can contain graphene, graphene oxide, reduced graphene oxide,graphene fluoride, doped graphene, functionalized graphene, expandedgraphite with an inter-graphene spacing greater than 0.4 nm, exfoliatedgraphite, chemically etched or expanded soft carbon, chemically etchedor expanded hard carbon, exfoliated activated carbon, chemically etchedor expanded carbon black, chemically etched multi-walled carbonnanotube, nitrogen-doped carbon nanotube, boron-doped carbon nanotube,chemically doped carbon nanotube, ion-implanted carbon nanotube,chemically treated multi-walled carbon nanotube with an inter-grapheneplanar separation no less than 0.4 nm, chemically expanded carbonnano-fiber, chemically activated or expanded carbon nano-tube, carbonfiber, graphite fiber, carbonized polymer fiber, coke, meso-phasecarbon, or a combination thereof. The expanded spacing ispreferably >0.5 nm, more preferably >0.6 nm, and most preferably >0.8nm.

Alternatively, the meso-porous structure may contain a porous,electrically conductive material selected from metal foam, carbon-coatedmetal foam, graphene-coated metal foam, metal web or screen,carbon-coated metal web or screen, graphene-coated metal web or screen,perforated metal sheet, carbon-coated porous metal sheet,graphene-coated porous metal sheet, metal fiber mat, carbon-coatedmetal-fiber mat, graphene-coated metal-fiber mat, metal nanowire mat,carbon-coated metal nanowire mat, graphene-coated metal nano-wire mat,surface-passivated porous metal, porous conductive polymer film,conductive polymer nano-fiber mat or paper, conductive polymer foam,carbon foam, carbon aerogel, carbon xerox gel, graphene foam, grapheneoxide foam, reduced graphene oxide foam, or a combination thereof. Theseporous and electrically conductive materials are capable ofaccommodating phthalocyanine compound in their pores and, in many cases,capable of protecting the phthalocyanine compound from getting dissolvedin a liquid electrolyte, in addition to providing a 3-D network ofelectron-conducting paths.

Conductive polymer nano-fiber mats can be readily produced byelectro-spinning of a conductive polymer, which can be an intrinsicallyconductive (conjugate-chain) polymer or a conductive filler-filledpolymer. Electro-spinning is well-known in the art. The production ofcarbon foam, carbon aerogel, or carbon Xerox gel is also well-known inthe art.

Particularly useful metal foams include copper foam, stainless steelfoam, nickel foam, titanium foam, and aluminum foam. The fabrication ofmetal foams is well known in the art and a wide variety of metal foamsare commercially available. Preferably, the surfaces of metallic foamsare coated with a thin layer of carbon or graphene because carbon andgraphene are more electrochemically inert and will not get dissolvedduring the charge/discharge cycles of the cell. Hence, carbon-coatedmetal foam, graphene-coated metal foam, carbon-coated metal web orscreen, graphene-coated metal web or screen, carbon-coated porous metalsheet, graphene-coated porous metal sheet, carbon-coated metal-fibermat, graphene-coated metal-fiber mat, carbon-coated metal nanowire mat,and graphene-coated metal nano-wire mat are preferred current collectormaterials for use in the rechargeable lithium cell. Also particularlyuseful are carbon foam, carbon aerogel, carbon xerox gel, graphene foam,graphene oxide foam, and reduced graphene oxide foam. These foams may bereinforced with a binder resin, conductive polymer, or CNTs to make acurrent collector of good structural integrity.

In one preferred embodiment, highly porous graphitic or carbonaceousmaterials may be used to make a conductive and protective backbonestructure prior to impregnating the resulting porous structure with aphthalocyanine compound. In this approach, particles of these materialsmay be bonded by a binder to form a porous structure of good structuralintegrity. Impregnation of the pores with a phthalocyanine compound canthen be accomplished through melt immersion or infiltration, physicalvapor infiltration, chemical vapor infiltration, solution dipping andimpregnation, etc.

In another possible route, porous graphitic or carbonaceous materialparticles, along with a resin binder, may be coated onto surfaces of ahighly porous metal framework with large pores, such as a metal foam,web, or screen, which serves as a backbone for a meso-porous structure.The combined hybrid structure is preferably very porous with a specificsurface area significantly greater than 100 m²/g. Impregnation of thepores with a phthalocyanine compound can then be accomplished throughmelt immersion or infiltration, physical vapor infiltration, chemicalvapor infiltration, solution dipping and impregnation, etc.

In yet another possible route, a phthalocyanine compound may be madeinto a fine powder form. Particles of the phthalocyanine compound andparticles of a porous graphitic or carbonaceous material, along with anoptional resin binder, are then mixed and bonded to a layer of cathodecurrent collector.

More desirable porous graphitic or carbonaceous materials for practicingthe instant invention are further described below:

As schematically illustrated in FIG. 3, a natural or artificial graphiteparticle is typically composed of several graphite crystal grains orcrystallites (3 being shown) with each crystallite made up of multiplegraphene planes bonded via van der Waals forces in the c-direction (adirection perpendicular to the graphene plane). The inter-graphene planespacing, d₀₀₂ as measured by X-ray diffraction, is typically from 0.335nm (natural graphite) to 0.337 (artificial graphite). Graphiteparticles, without any chemical intercalation, oxidation, fluorination,etc, can be dispersed in water containing a surfactant and the resultingsuspension subjected to high-power ultrasonic wave treatment to producepristine graphene, a process commonly referred to as directultrasonication or liquid phase production. The resulting pristinegraphene sheets are relatively defect-free and exhibit exceptionalthermal conductivity and electric conductivity.

Alternatively, as illustrated in the upper-right portion of FIG. 3,graphite particles may be subjected to an oxidation treatment,fluorination treatment (or other types of halogenation or chemicalexpansion treatments), or intercalation (e.g. in a mixture of sulfuricacid and nitric acid) to produce graphite oxide (GO), graphite fluoride(GF), or graphite intercalation compound (GIC). The GO, GF, or GIC maybe subsequently subjected to an ultrasonication treatment toexfoliate/separate graphene planes, forming isolated (separated)graphene oxide or graphene fluoride sheets. Alternatively, the GO, GF,or GIC may be subsequently subjected to a thermal exfoliation treatment(typically in a temperature of 150-1200° C., more typically 650-1050°C.) to obtain exfoliated graphite (or graphite worms). A graphite wormis a worm-like, highly porous structure composed of networks of weaklyinterconnected graphite flakes and/or graphene sheets. Two SEM images ofgraphite worms are presented in FIGS. 4(A) and (B).

A mass of graphite worms may be roll-pressed to obtain a flexiblegraphite sheet, which may be used as a solid (relatively non-porous)current collector in a conventional lithium-ion battery. However, such aprior art flexible graphite sheet is relatively pore-free on the sheetsurface and could not be penetrated by liquid electrolyte. Further, theconstituent graphite flakes are compressed and re-stacked together and,hence, are not accessible by liquid electrolyte. The flexible graphitesheet is not meso-porous, and the specific surface area of theconventional flexible graphite sheet is typically much <10 m²/g.Furthermore, the flexible graphite sheet itself has a very low lithiumstorage capability (typically <<100 mAh/g) and, hence, has not beenconsidered a suitable lithium storage material.

By contrast, we have found a way to preserve the porous characteristicsof graphite worms. Without breaking up the links between constituentgraphite flakes of a worm, graphite worms may be lightly impregnatedwith a binder resin, which is cured or solidified to impart structuralintegrity to the worms (which are otherwise very fluffy and weak). Thecuring or solidifying procedure may be conducted while the graphite wormmass is under a light and controlled pressure. The resulting mass is anintegral sheet of porous graphite worm foam with a high specific surfacearea (typically >100 m²/g and more typically >200 m²/g). The resinbinder may be optionally carbonized to further increase the conductivityof the graphite worm foam and its ability to capture metal ions ongraphite flake surfaces.

Graphite worms, as exfoliated (without a binder), may be optionallysubjected to mechanical shearing (e.g. air-jet milling) to producegraphite flakes. These flakes would have a thickness >100 nm, if theoriginal graphite has received insufficient oxidation, fluorination, orintercalation treatment prior to the thermal exfoliation step. Theseflakes can become nano graphene platelets (NGPs) with a thickness <100nm and more typically <10 nm (including multi-layer graphene plateletsor single-layer graphene sheets, as thin as 0.34 nm) if the originalgraphite has been heavily oxidized, fluorinated, or intercalated. Thegraphite worms or the isolated graphene platelets/sheets (NGPs) may befurther subjected to a chemical activation or etching treatment togenerate more defects or pores therein or thereon. A plurality of NGPsmay be re-constituted into various porous structures or morphologies(e.g. porous graphene sphere, curved graphene sheets, wrinkled graphene,etc) having a pore size in the range of 2 to 50 nm when they areaggregated and bonded together. The resulting porous structure having ahigh specific surface area makes a good current collector, which is alsocapable of storing large amounts of metal on graphene surfaces.

In particular, the meso-porous structure to support the phthalocyaninecompound in the cathode of the presently invented lithium cell ispreferably made from a graphene material selected from a single-layersheet or multi-layer platelet of graphene, graphene oxide, graphenefluoride, hydrogenated graphene, nitrogenated graphene, pristinegraphene, doped graphene, boron doped graphene, nitrogen doped graphene,chemically treated graphene, reduced graphene oxide, functionalizedgraphene or graphene oxide, or a combination thereof. In the presentapplication, nano graphene platelets (NGPs) or “graphene materials”collectively refer to single-layer and multi-layer versions of graphene,graphene oxide, graphene fluoride, hydrogenated graphene, nitrogenatedgraphene, doped graphene, etc.

The thickness of an NGP is no greater than 100 nm and, in the presentapplication, no greater than 10 nm (preferably no greater than 5 nm).The NGP is preferably single-layer graphene or few-layer graphene (lessthan 10 graphene planes). In the presently defined NGPs, there is nolimitation on the length and width, but they are preferably smaller than10 μm and more preferably smaller than 1 μm. We have been able toproduce NGPs with length smaller than 100 nm or larger than 10 μm. TheNGP can be pristine graphene (with essentially 0% oxygen content) orgraphene oxide (typically from 10 up to approximately 45% by weightoxygen). Graphene oxide can be thermally or chemically reduced to becomereduced graphene oxide (typically with an oxygen content of 1-10%,mostly below 5% by weight). For use in the cathode of the lithium-ioncell, the oxygen content is preferably in the range of 0% to 10% byweight, and more preferably in the range of 0% to 5% by weight. Thespecific surface area accessible to liquid electrolyte is the singlemost important parameter in dictating the energy and power densities ofa lithium-ion cell of the present invention. Thus, it is highlydesirable to pack multiple graphene sheets into a meso-porous structurehaving a pore size of 2-50 nm, more preferably 5-20 nm.

Despite the fact that individual graphene sheets have an exceptionallyhigh specific surface area, flat-shaped graphene sheets prepared byconventional routes have a great tendency to re-stack together oroverlap with one another, thereby dramatically reducing the specificsurface area that is accessible by the electrolyte. We have developed anew breed of graphene, herein referred to as the curved grapheneplatelet or sheet. Curved NGPs are capable of forming a meso-porousstructure having a desired pore size range (e.g. slightly >2 nm) whenthey were stacked together to form an electrode. This size range appearsto be conducive to being accessible by the commonly usedlithium-containing electrolytes.

The curved NGPs may be produced by using the following recommendedprocedures:

-   (a) dispersing or immersing a laminar graphite material (e.g.,    natural graphite powder) in a mixture of an intercalant and an    oxidant (e.g., concentrated sulfuric acid and nitric acid,    respectively) to obtain a graphite intercalation compound (GIC) or    graphite oxide (GO);-   (b) exposing the resulting GIC or GO to a thermal shock, preferably    in a temperature range of 600-1,100° C. for a short period of time    (typically 15 to 60 seconds), to obtain exfoliated graphite or    graphite worms (some oxidized NGPs with a thickness <100 nm could be    formed at this stage if the intercalation/oxidation step was allowed    to proceed for a sufficiently long duration of time; e.g. >24    hours);-   (c) dispersing the exfoliated graphite to a liquid medium to obtain    a graphene-liquid suspension (a functionalizing agent may be added    into this suspension if functional groups are desired, as in our    co-pending application);-   (d) aerosolizing the graphene-liquid suspension into liquid droplets    while concurrently removing the liquid to recover curved NGPs.    Without the aerosolizing step, the resulting graphene platelets tend    to be flat-shaped.

It may be noted that steps (a) to (b) are the most commonly used stepsto obtain exfoliated graphite and graphene oxide platelets in the field.Step (d) is essential to the production of curved graphene sheets.Oxidized NGPs or GO platelets may be chemically reduced to recoverconductivity properties using hydrazine as a reducing agent, before,during, or after chemical functionalization.

In 2007, we reported a direct ultrasonication method of producingpristine nano graphene directly from graphite particles dispersed in asurfactant-water suspension [A. Zhamu, et al, “Method of ProducingExfoliated Graphite, Flexible Graphite, and Nano-Scaled GraphenePlates,” U.S. patent application Ser. No. 11/800,728 (May 8, 2007)].This method entails dispersing natural graphite particles in a lowsurface tension liquid, such as acetone or hexane. The resultingsuspension is then subjected to direct ultrasonication for 10-120minutes, which produces graphene at a rate equivalent to 20,000 attemptsto peel off graphene sheets per second per particle. The graphite hasnever been intercalated or oxidized and, hence, requires no subsequentchemical reduction. This method is fast, environmentally benign, and canbe readily scaled up, paving the way to the mass production of pristinenano graphene materials. The same method was later studied by others andnow more commonly referred to as the “liquid phase production.”

When a multi-layer graphene platelet is present in the cathode of thepresently invented lithium-ion cell, the discharge operation of the cellcan involve intercalating lithium into an inter-graphene space in amulti-layer graphene platelet and capturing and storing lithium onsurfaces of a single-layer graphene sheet (if present) or multi-layergraphene platelet.

Nitrogenated graphene, nitrogen-doped graphene, or boron-doped graphenecan be produced from chemical synthesis, chemical vapor deposition(CVD), or ion implantation. For instance, nitrogen-doped graphene can beproduced from CVD using CH₄ as a carbon source, NH₃ as a nitrogensource, nano-scaled Cu/Ni particles (or Cu, Ni, or Cu/Ni, foil) as acatalyst. Boron-doped graphene can be produced by boron ionimplantation.

The approach used to combine a phthalocyanine compound and a carbon orgraphite material (e.g. graphene material or chemically treated softcarbon) to form a hybrid cathode active material has a truly unexpectedand profound impact on the chemical composition, microstructure,morphology, and properties of the resulting hybrid material. All of theporous carbon/graphite material particles can be packed, along with aresin binder, into a meso-porous structure. Metal foams are already ahighly porous structure, and mats of electro-spun conductive nano-fibersare also porous. The phthalocyanine compound can then be infiltratedinto pores of the meso-porous structure.

Alternatively, the porous carbon or graphite material may be initiallyin a fine powder form, prior to being packed into a meso-porousstructure. In this case, the formation of a meso-porous structure may beallowed to occur concurrently with the mixing of a phthalocyaninecompound. These are further discussed in several examples toward the endof this specification.

Approaches that can be used for combining a porous conductive materialand a phthalocyanine compound include, but are not limited to, thefollowing:

-   -   (1) Dry powder mixing: Most of the phthalocyanine compounds are        available in a powder form, so are all graphene materials and        some porous carbon or graphite materials. The most        straightforward way of mixing these two dry powder ingredients        is through a wide variety of drying powder mixing processes        (e.g. tumbling mixing, air jet mixing, and mixture grinding)        However, the resulting mixtures, when used as a cathode active        material for a rechargeable lithium metal or lithium-ion cell,        deliver the worst performance as compared to those prepared by        other methods discussed below.    -   (2) High-intensity ball-milling: The phthalocyanine compound        powder and porous carbon/graphite material powder may be mixed        to form a powder mixture, which is then subjected to        ball-milling. Ball milling may be preceded by a dry mixing        procedure.    -   (3) Co-precipitation: A solution or suspension of a        phthalocyanine compound and a solution or suspension of a        graphene material in a common solvent or dispersing liquid        medium may be mixed to form a solution or suspension. The        solvent or liquid is then removed to enable co-precipitation of        the phthalocyanine compound and the graphene material to form an        intimately mixed and interacted hybrid material. After an        extensive and in-depth study, we have observed that various        graphene materials are effective heterogeneous nucleating agents        for phthalocyanine compounds and the 2-D nano geometric nature        also acts to constraint the growth of phthalocyanine compound        crystals in both thickness and lateral dimensions. We have also        observed that the phthalocyanine compound and the graphene        material have a great natural affinity to develop π-π        interactions, providing effective charge transfer during the        charge and discharge of a lithium cell. This seems to have        played a critical role in reducing the solubility of        phthalocyanine in the electrolyte or reducing the catalytic        effect of phthalocyanine in decomposing the electrolyte. These        are yet another two unexpected effects.    -   (4) Vapor-phase deposition of phthalocyanine compound molecules        on graphene material surfaces or exfoliated graphite flake        surfaces: Most of the phthalocyanine compounds can be vaporized        or sublimed at a temperature in the range of 250-700° C.    -   (5) Melt mixing: One can disperse graphene sheets in a        phthalocyanine compound melt in a protective atmosphere to form        a composite fluid, which is then extruded and pelletized.

Alternatively and advantageously, multiple graphene sheets can becombined into individual secondary particles that are highly porous(preferably having a pore size in the range of 1-100 nm, more preferably2-50 nm, and most preferably 5-20 nm). These secondary particles,typically 1-20 μm in size, are then packed and bonded with a binder toform a meso-porous backbone structure having pores to accommodate. Thepores (preferably 2-50 nm in size) of this meso-porous backbonestructure is then impregnated with a phthalocyanine compound throughmelt infiltration, vapor phase infiltration, liquid solutionimpregnation, etc.

In general, the cathode active material (including the porous backbonestructure and the phthalocyanine compound lodged in the pores) as awhole also preferably form a meso-porous structure with a desired amountof meso-scaled pores (2-50 nm, preferably 2-10 nm) to allow the entry ofelectrolyte. This is advantageous because these pores enable a greatamount of surface areas to be in physical contact with electrolyte andcapable of capturing lithium from the electrolyte. These surface areasof the cathode active material as a whole are typically andpreferably >50 m²/g, more preferably >500 m²/g, further morepreferably >1,000 m²/g, and most preferably >1,500 m²/g.

The presently invented cell also contains a negative electrode (anode)comprising an anode active material for inserting and extracting lithiumduring the charge and discharge of the cell, wherein the anode activematerial is mixed with a conductive additive and/or a resin binder toform a porous electrode structure, or coated onto a current collector ina coating or thin film form (e.g. film thickness <100 μm). The anodeactive material preferably has a lithium storage capacity greater than400 mAh/g (more preferably greater than 1,000 mAh/g, and most preferablygreater than 2,000 mAh/g). The anode active material is preferablynano-scaled material having a dimension less than 100 nm, preferablyless than 20 nm.

It may be noted that graphite crystals in a graphitic or carbonaceousmaterial contain graphene planes having an inter-graphene plane spacingof approximately 0.34 nm. We have experimentally observed that, byoxidizing or fluorinating the graphite crystals one can increase theinter-graphene spacing to >0.40 nm, more typically >0.50 nm, and mosttypically >0.60 nm. We have further observed that these expandedgraphite crystals with extra spaces between graphene planes canaccommodate great amounts of lithium atoms when used as an anode activematerial.

This cell preferably contains a meso-porous graphitic or carbonaceousmaterial-based anode containing active surfaces for capturing andstoring lithium atoms thereon. The graphitic material may be selectedfrom graphene sheets, graphite worms, exfoliated graphite flakes,expanded graphite, chemically treated graphite with an inter-grapheneplanar separation no less than 0.4 nm (preferably greater than 0.5 nm,more preferably greater than 0.6 nm, most preferably greater than 0.8nm), soft carbon (preferably, chemically etched or expanded softcarbon), hard carbon (preferably, chemically etched or expanded hardcarbon), activated carbon (preferably, exfoliated activated carbon),carbon black (preferably, chemically etched or expanded carbon black),chemically expanded multi-walled carbon nano-tube, chemically expandedcarbon nano-fiber, or a combination thereof. The graphitic materialoptionally may also have the capability to store some lithium in thebulk (interior) of graphitic material particles.

The rechargeable Li cell further contains a porous separator disposedbetween the anode and the cathode; a lithium-containing electrolyte inphysical contact with the two electrodes (the anode and the cathode);and a lithium source disposed in the anode (if the anode active materialis not pre-lithiated) when the cell is made. In one preferredembodiment, the anode active material is not pre-lithiated and islithium-free when the cell is made.

Several types of lithium sources may be implemented to provide thelithium ions that are needed for shuttling between the anode and thecathode. Examples of the sources are a lithium chip, lithium alloy chip,lithium foil, lithium alloy foil, lithium powder, lithium alloy powder,surface stabilized lithium particles, a mixture of lithium metal orlithium alloy with a lithium intercalation compound, lithium or lithiumalloy film coated on a surface of an anode or cathode active material,or a combination thereof.

In this preferred embodiment of the present invention, the anode activematerial is not prelithiated since there is a lithium ion sourcealready. In particular, the anode active material is a non-prelithiatedmaterial selected from the group consisting of: (a) Non-lithiatedsilicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb),bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti), cobalt (Co),nickel (Ni), manganese (Mn), cadmium (Cd), and mixtures thereof; (b)Non-lithiated alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb,Bi, Zn, Al, Ti, Co, Ni, Mn, Cd, and their mixtures; (c) Non-lithiatedoxides, carbides, nitrides, sulfides, phosphides, selenides, tellurides,or antimonides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ti, Co, Ni, Mn,Cd, and mixtures or composites thereof; (d) Non-lithiated salts orhydroxides of Sn; and (e) graphite or carbon material in a powder orfibrous form. Unless the anode active material is directly coated onto acurrent collector, the anode active material is typically mixed with aconductive additive and/or a resin binder to form a porous electrodestructure that is electrically connected to the anode current collector.

During the first discharge cycle of the cell after it is made, thelithium source releases lithium ions into the electrolyte. These lithiumions in the electrolyte migrate through the porous separator into thecathode and get captured by the cathode, via surface-capturing of Li (Liadsorbed on surfaces of phthalocyanine molecules or surfaces of graphenesheets) and Li intercalation (into inter-molecular spaces in aphthalocyanine compound crystal or inter-graphene spaces in amulti-layer graphene platelet).

During the subsequent re-charge of the cell, lithium ions are releasedfrom the cathode and migrate back to the anode side. These lithium ionsthen intercalate into the interior of anode active material particles orcoating, or get captured by graphene surfaces when available. Thesubsequent discharge cycle involves releasing lithium ions from theanode active material through de-intercalation, de-sorption, ordissolution. In a preferred embodiment, the aforementioned non-lithiatedanode active material is in the form of a nano particle, nano disc, nanoplatelet, nano wire, nano-rod, nano belt, nano scroll, nano tube, nanofilament, nano coating, or nano film, having a dimension less than 100nm, preferably less than 20 nm.

Preferably, the anode active material contains a mixture of a highcapacity anode material and a high rate capable anode material, whereinthe high rate capable anode material is selected from nano-scaledparticles or filaments of a transition metal oxide, Co₃O₄, Mn₃O₄, Fe₃O₄,or a combination thereof, and the high capacity anode material isselected from Si, Ge, Sn, SnO, or a combination thereof. Nano-scaledparticles or filaments have a dimension (e.g. diameter or thickness)less than 100 nm, enabling a short lithium diffusion time and high powerdensity.

It has been commonly believed that a high specific surface area is anundesirable feature of either an anode or a cathode for a lithium-ioncell based on the belief that a higher surface area leads to theformation of more solid-electrolyte interface (SEI), a common cause ofcapacity irreversibility or capacity loss. We have herein defied thisexpectation and discovered that the meso-porous hybrid cathode materialscan be superior cathode materials for lithium-ion cells, which couldoperate thousands of cycles without any significant capacity decay. Thisis so in spite of or despite of the notion that both graphite and carbonmaterials (including nano graphene), when used as an anode activematerial, have serious SEI issue. This is truly unexpected.

Even more surprisingly, the meso-porous phthalocyanine/graphene hybridmaterials, when incorporated as a cathode active material having aspecific surface area greater than 50 m²/g and pores of 2-50 nm in size,exhibit a specific capacity significantly higher than that of anycommonly used lithium ion cell cathode. For instance, the micron-sizedlayered LiCoO₂ used in a lithium-ion battery exhibits a specificcapacity typically lower than 160 mAh/g. The highest-capacity cathodeactive material for the lithium-ion cell is likely vanadium oxide thathas a theoretical specific capacity of approximately 430 mAh/g, but apractically achievable capacity of 250 mAh/g. In contrast, we haveroutinely achieved a cathode specific capacity of 500-2,200 mAh/g when ameso-porous hybrid material is used as a cathode active material in arechargeable lithium metal or lithium-ion cell.

In an embodiment of the present invention, one may choose to add aconductive additive and/or a binder material (e.g. binder resin orcarbonized resin) to form an electrode (cathode or anode) of structuralintegrity. A conductive additive is generally needed in the anode of thepresently invented lithium-ion cell since many of the non-carbon ornon-graphite based anode active materials are inorganic materials (e.g.,Si, SnO, and Mn₃O₄) that are not electrically conducting. The conductiveadditive or filler may be selected from any electrically conductivematerial, but is advantageously selected from graphite or carbonparticles, carbon black, expanded graphite, graphene, carbon nanotube,carbon nano-fiber, carbon fiber, conductive polymer, or a combinationthereof. The amount of conductive fillers is preferably no greater than30% by weight based on the total cathode electrode weight (withoutcounting the cathode current collector weight), preferably no greaterthan 15% by weight, and most preferably no greater than 10% by weight.The amount of binder material is preferably no greater than 15% byweight, more preferably no greater than 10%, and most preferably nogreater than 5% by weight.

Preferred electrolyte types include liquid electrolyte, gel electrolyte,polymer electrolyte, solid electrolyte, and ionic liquid electrolyte(preferably containing lithium salts dissolved therein), or acombination thereof.

Although there is no limitation on the electrode thickness, thepresently invented positive electrode preferably has a thickness greaterthan 100 μm, more preferably greater than 150 μm, and most preferablygreater than 200 μm.

Another preferred embodiment of the present invention is a rechargeablelithium cell comprising: (a) an anode comprising an anode activematerial, wherein said anode active material is a prelithiated lithiumstorage material; (b) a cathode comprising a hybrid cathode activematerial composed of a graphene material and a phthalocyanine compound,wherein the graphene material is in an amount of from 0.1% to 99% byweight based on the total weight of the graphene material and thephthalocyanine compound combined; and (c) a porous separator disposedbetween the anode and the cathode and electrolyte in ionic contact withthe anode and the cathode.

In this cell, the prelithiated lithium storage material in the anode ispreferably in the form of a nano particle, nano disc, nano platelete,nano wire, nano-rod, nano belt, nano scroll, nano tube, nano filament,nano coating, or nano film. The pre-lithiated lithium storage materialmay be selected from: (a) a pre-lithiated silicon (Si), germanium (Ge),tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum(Al), titanium (Ti), cobalt (Co), nickel (Ni), manganese (Mn), cadmium(Cd), or a mixture thereof; (b) a pre-lithiated alloy or intermetalliccompound of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Co, Ni, Mn, Cd, or amixture thereof; (c) a pre-lithiated oxide, carbide, nitride, sulfide,phosphide, selenide, telluride, or antimonide of Si, Ge, Sn, Pb, Sb, Bi,Zn, Al, Fe, Ti, Co, Ni, Mn, Cd, or a mixture or composite thereof, (d) apre-lithiated salt or hydroxide of Sn; or (e) a pre-lithiated carbon orgraphite material. Preferably, this anode active material iselectrically connected directly to an anode current collector or isconnected to an anode current collector through a binder and/or aconductive additive.

In a further preferred embodiment, the anode active material contains amixture of a high capacity anode material and a high rate capable anodematerial, wherein the high rate capable anode material is selected fromnano-scaled particles or filaments of a lithium transition metal oxide,lithiated Co₃O₄, lithiated Mn₃O₄, lithiated Fe₃O₄, Li₄Ti₅O₁₂, or acombination thereof, and the high capacity anode material is selectedfrom pre-lithiated Si, Ge, Sn, SnO, or a combination thereof.

Preferably, the anode active material is prelithiated to an initialspecific capacity of no less than 500 mAh/g (more preferably no lessthan 700 mAh/g, even more preferably no less than 1,000 mAh/g, furtherpreferably no less than 1,500 mAh/g, and most preferably no less than2,000 mAh/g) based on the anode active material weight. Preferably, whenthe lithium-ion cell containing such a prelithiated anode activematerial is discharged, the anode active material is not fullydischarged; instead, the anode active material maintains at least 50% ofthe initial specific capacity. Materials such as Si, Ge, and Sn oxidecan be prelithiated to an initial capacity of >1000 mAh/g; Si can beprelithiated to >4,000 mAh/g. These are preferred choices for an anodeactive material.

The carbonaceous or graphitic material for use in the anode of theinstant invention may be graphite worms, exfoliated graphite flakes(with a thickness >100 nm), expanded graphite (with a thickness >100nm), chemically treated graphite with an inter-graphene planarseparation no less than 0.4 nm (preferably greater than 0.5 nm, morepreferably greater than 0.6 nm), soft carbon (preferably, chemicallyetched or expanded soft carbon), hard carbon (preferably, chemicallyetched or expanded hard carbon), activated carbon (preferably,exfoliated activated carbon), carbon black (preferably, chemicallyetched or expanded carbon black), chemically expanded multi-walledcarbon nano-tube, chemically expanded carbon fiber or nano-fiber, or acombination thereof. These carbonaceous or graphitic materials have onething in common; they all have meso-scaled pores, enabling entry ofelectrolyte to access their interior graphene planes.

In one preferred embodiment, the meso-porous carbonaceous or graphiticmaterial may be produced by using the following recommended procedures:

-   -   (A) dispersing or immersing a graphitic or carbonaceous material        (e.g., powder of natural graphite, artificial graphite,        meso-phase carbon, meso-carbon micro bead (MCMB), soft carbon,        hard carbon, coke, polymeric carbon (carbonized resin),        activated carbon (AC), carbon black (CB), multi-walled carbon        nanotube (MWCNT), carbon nano-fiber (CNF), carbon or graphite        fiber, meso-phase pitch fiber, and the like) in a mixture of an        intercalant and/or an oxidant (e.g., concentrated sulfuric acid        and nitric acid) and/or a fluorinating agent to obtain a        graphite intercalation compound (GIC), graphite oxide (GO),        graphite fluoride (GF), or chemically etched/treated carbon        material;    -   (B) exposing the resulting GIC, GO, GF, or chemically        etched/treated carbon material to a thermal shock, preferably in        a temperature range of 600-1,100° C. for a short period of time        (typically 15 to 60 seconds) to obtain exfoliated graphite or        graphite worms; and optionally    -   (C) subjecting the resulting graphite worms to air jet milling        to obtain expanded graphite (with graphite flakes thicker than        100 nm).        Alternatively, after step (A) above, the resulting GIC, GO, GF,        or chemically etched/treated carbon/graphite material is        subjected to repeated rinsing/washing to remove excess chemical.        The rinsed products are then subjected to a drying procedure to        remove water. The dried GO, GF, chemically treated CB,        chemically treated AC, chemically treated MWCNT, chemically        treated CNF, chemically treated carbon/graphite/pitch fiber can        be used as a cathode active material of the presently invented        high-capacity Li-ion cell. These chemically treated carbonaceous        or graphitic materials can be further subjected to a heat        treatment at a temperature preferably in the range of        150-1,100° C. for the purposes of thermally reducing the        oxidized material, thermally exfoliating/expanding the        carbonaceous/graphitic material (for increasing inter-planar        spacing between two hexagonal carbon planes or graphene planes),        and/or creating meso-scaled pores (2-50 nm) to enable the        interior structure being accessed by electrolyte. It may be        noted that these interior graphene planes remain stacked and        interconnected with one another, but the above-described        chemical/thermal treatments facilitate direct access of these        interior graphene planes by lithium ion-carrying electrolyte.

The broad array of carbonaceous materials, such as a soft carbon, hardcarbon, polymeric carbon (or carbonized resin), meso-phase carbon, coke,carbonized pitch, carbon black, activated carbon, or partiallygraphitized carbon, are commonly referred to as the disordered carbonmaterial. A disordered carbon material is typically formed of two phaseswherein a first phase is small graphite crystal(s) or small stack(s) ofgraphite planes (with typically up to 10 graphite planes or aromaticring structures overlapped together to form a small ordered domain) anda second phase is non-crystalline carbon, and wherein the first phase isdispersed in the second phase or bonded by the second phase. The secondphase is made up of mostly smaller molecules, smaller aromatic rings,defects, and amorphous carbon. Typically, the disordered carbon ishighly porous (e.g., exfoliated activated carbon), or present in anultra-fine powder form (e.g. chemically etched carbon black) havingnano-scaled features (e.g. having meso-scaled pores and, hence, a highspecific surface area).

Soft carbon refers to a carbonaceous material composed of small graphitecrystals wherein the orientations of these graphite crystals or stacksof graphene planes inside the material are conducive to further mergingof neighboring graphene sheets or further growth of these graphitecrystals or graphene stacks using a high-temperature heat treatment.This high temperature treatment is commonly referred to asgraphitization and, hence, soft carbon is said to be graphitizable.

Hard carbon refers to a carbonaceous material composed of small graphitecrystals wherein these graphite crystals or stacks of graphene planesinside the material are not oriented in a favorable directions (e.g.nearly perpendicular to each other) and, hence, are not conducive tofurther merging of neighboring graphene planes or further growth ofthese graphite crystals or graphene stacks (i.e., not graphitizable).

Carbon black (CB) (including acetylene black, AB) and activated carbon(AC) are typically composed of domains of aromatic rings or smallgraphene sheets, wherein aromatic rings or graphene sheets in adjoiningdomains are somehow connected through some chemical bonds in thedisordered phase (matrix). These carbon materials are commonly obtainedfrom thermal decomposition (heat treatment, pyrolyzation, or burning) ofhydrocarbon gases or liquids, or natural products (wood, coconut shells,etc). These materials per se (without chemical/thermal treatments asdescribed above) are not good candidate cathode materials for thepresently invented high-capacity Li-ion cells. Hence, preferably, theyare subjected to further chemical etching or chemical/thermalexfoliation to form a meso-porous structure having a pore size in therange of 2-50 nm (preferably 2-10 nm). These meso-scaled pores enablethe liquid electrolyte to enter the pores and access the graphene planesinside individual particles of these carbonaceous materials.

The preparation of polymeric carbons by simple pyrolysis of polymers orpetroleum/coal tar pitch materials has been known for approximatelythree decades. When polymers such as polyacrylonitrile (PAN), rayon,cellulose and phenol formaldehyde were heated above 300° C. in an inertatmosphere they gradually lost most of their non-carbon contents. Theresulting structure is generally referred to as a polymeric carbon.Depending upon the heat treatment temperature (HTT) and time, polymericcarbons can be made to be insulating, semi-conducting, or conductingwith the electric conductivity range covering approximately 12 orders ofmagnitude. This wide scope of conductivity values can be furtherextended by doping the polymeric carbon with electron donors oracceptors. These characteristics uniquely qualify polymeric carbons as anovel, easy-to-process class of electro-active materials whosestructures and physical properties can be readily tailor-made.

Polymeric carbons can assume an essentially amorphous structure, or havemultiple graphite crystals or stacks of graphene planes dispersed in anamorphous carbon matrix. Depending upon the HTT used, variousproportions and sizes of graphite crystals and defects are dispersed inan amorphous matrix. Various amounts of two-dimensional condensedaromatic rings or hexagons (precursors to graphene planes) can be foundinside the microstructure of a heat treated polymer such as a PAN fiber.An appreciable amount of small-sized graphene sheets are believed toexist in PAN-based polymeric carbons treated at 300-1,000° C. Thesespecies condense into wider aromatic ring structures (larger-sizedgraphene sheets) and thicker plates (more graphene sheets stackedtogether) with a higher HTT or longer heat treatment time (e.g., >1,500°C.). These graphene platelets or stacks of graphene sheets (basalplanes) are dispersed in a non-crystalline carbon matrix. Such atwo-phase structure is a characteristic of some disordered carbonmaterial.

There are several classes of precursor materials to the disorderedcarbon materials of the instant patent application. For instance, thefirst class includes semi-crystalline PAN in a fiber form. As comparedto phenolic resin, the pyrolized PAN fiber has a higher tendency todevelop small crystallites that are dispersed in a disordered matrix.The second class, represented by phenol formaldehyde, is a moreisotropic, essentially amorphous and highly cross-linked polymer. Thethird class includes petroleum and coal tar pitch materials in bulk orfiber forms. The precursor material composition, heat treatmenttemperature (HTT), and heat treatment time (Htt) are three parametersthat govern the length, width, thickness (number of graphene planes in agraphite crystal), and chemical composition of the resulting disorderedcarbon materials.

In the present investigation, PAN fibers were subjected to oxidation at200-350° C. while under a tension, and then partial or completecarbonization at 350-1,500° C. to obtain polymeric carbons with variousnano-crystalline graphite structures (graphite crystallites). Selectedsamples of these polymeric carbons were further heat-treated at atemperature in the range of 1,500-2,000° C. to partially graphitize thematerials, but still retaining a desired amount of amorphous carbon (noless than 10%). Phenol formaldehyde resin and petroleum and coal tarpitch materials were subjected to similar heat treatments in atemperature range of 500 to 1,500° C. The disordered carbon materialsobtained from PAN fibers or phenolic resins are preferably subjected toa chemical etching/expanding treatment using a process commonly used toproduce activated carbon (e.g., treated in a KOH melt at 900° C. for 1-5hours). This chemical treatment is intended for making the disorderedcarbon meso-porous, enabling electrolyte to reach the edges or surfacesof the constituent aromatic rings after a battery cell is made. Such anarrangement enables the lithium ions in the liquid electrolyte toreadily attach onto exposed graphene planes or edges without having toundergo significant solid-state diffusion.

Certain grades of petroleum pitch or coal tar pitch may be heat-treated(typically at 250-500° C.) to obtain a liquid crystal-type, opticallyanisotropic structure commonly referred to as meso-phase. Thismeso-phase material can be extracted out of the liquid component of themixture to produce isolated meso-phase particles or spheres, which canbe further carbonized and graphitized.

The following examples serve to illustrate the preferred embodiments ofthe present invention and should not be construed as limiting the scopeof the invention:

Example 1 Graphene Oxide from Sulfuric Acid Intercalation andExfoliation of MCMBs

Meso-carbon microbeads (MCMBs) were supplied from China Steel ChemicalCo. This material has a density of about 2.24 g/cm³ with a medianparticle size of about 16 μm. MCMB (10 grams) were intercalated with anacid solution (sulfuric acid, nitric acid, and potassium permanganate ata ratio of 4:1:0.05) for 48 hours. Upon completion of the reaction, themixture was poured into deionized water and filtered. The intercalatedMCMBs were repeatedly washed in a 5% solution of HCl to remove most ofthe sulphate ions. The sample was then washed repeatedly with deionizedwater until the pH of the filtrate was neutral. The slurry was dried andstored in a vacuum oven at 60° C. for 24 hours. The dried powder samplewas placed in a quartz tube and inserted into a horizontal tube furnacepre-set at a desired temperature, 800° C. for 30 seconds to obtain agraphene material. A small quantity of each sample was mixed with waterand ultrasonicated at 60-W power for 10 minutes to obtain a suspension.A small amount was sampled out, dried, and investigated with TEM, whichindicated that most of the NGPs were between 1 and 10 layers. Thegraphene-water suspension was used for subsequent preparation of agraphene oxide (GO) cathode, a hybrid naphthalocyanine/GO cathode, and achemically bonded hybrid naphthalocyanine/GO cathode.

Example 2 Oxidation and Exfoliation of Natural Graphite to Produce GO

Graphite oxide was prepared by oxidation of graphite flakes withsulfuric acid, sodium nitrate, and potassium permanganate at a ratio of4:1:0.05 at 30° C. for 48 hours, according to the method of Hummers[U.S. Pat. No. 2,798,878, Jul. 9, 1957]. Upon completion of thereaction, the mixture was poured into deionized water and filtered. Thesample was then washed with 5% HCl solution to remove most of thesulfate ions and residual salt and then repeatedly rinsed with deionizedwater until the pH of the filtrate was approximately 7. The intent wasto remove all sulfuric and nitric acid residue out of graphiteinterstices. The slurry was dried and stored in a vacuum oven at 60° C.for 24 hours.

The dried, intercalated (oxidized) compound was exfoliated by placingthe sample in a quartz tube that was inserted into a horizontal tubefurnace pre-set at 1,050° C. to obtain highly exfoliated graphite. Theexfoliated graphite was dispersed in water along with a 1% surfactant at45° C. in a flat-bottomed flask and the resulting graphene oxide (GO)suspension was subjected to ultrasonication for a period of 15 minutes.The suspension was then atomized in a heated chamber to obtain poroussecondary particles that are approximately spherical in shape and 1-10μm in size. These particles were packed and bonded into a meso-porousbackbone structure to accommodate a phthalocyanine compound.

Example 3 Direct Ultrasonication of Natural Graphite to Produce PristineGraphene

In a typical procedure, five grams of graphite flakes, ground toapproximately 20 μm or less in sizes, were dispersed in 1,000 mL ofdeionized water (containing 0.1% by weight of a dispersing agent, Zonyl®FSO from DuPont) to obtain a suspension. An ultrasonic energy level of85 W (Branson S450 Ultrasonicator) was used for exfoliation, separation,and size reduction of graphene sheets for a period of 15 minutes to 2hours. The resulting products are pristine graphene suspended in a watersolution. The suspension can be made into conductive graphene paperhaving meso-scale pores via vacuum-assisted filtration, or made intographene foam (with or without an added water soluble polymer, such aspolyethylene oxide, PEO) using a freeze-drying procedure. A small amountof PEO (typically <0.1% by wt. in the water solution) was latercarbonized to form a carbon binder that serves to bond graphene sheetsinto a foam of good structural integrity. The pores of this graphenefoam can accommodate a phthalocyanine compound.

Example 4 Meso-Porous Soft Carbon as a Supporting and ProtectiveBackbone for a Phthalocyanine Compound

Chemically etched or expanded soft carbon was prepared fromheat-treating a liquid crystalline aromatic resin (50/50 mixture ofanthracene and pyrene) at 200° C. for 1 hour. The resin was ground witha mortar, and calcined at 900° C. for 2 h in a N₂ atmosphere to preparethe graphitizable carbon or soft carbon. The resulting soft carbon wasmixed with small tablets of KOH (four-fold weight) in an alumina meltingpot. Subsequently, the soft carbon containing KOH was heated at 750° C.for 2 h in N₂. Upon cooling, the alkali-rich residual carbon was washedwith hot water until the outlet water reached a pH value of 7. Theresulting chemically etched or expanded soft carbon was dried by heatingat 60° C. in a vacuum for 24 hours. This material can be used in boththe anode and cathode due to its high specific surface area and itsability to capture and store lithium atoms on its surfaces (if notcovered by a phthalocyanine compound). These surfaces (inside pores)were also found to be particularly suitable for supporting variousphthalocyanine compounds.

Example 5 Expanded “Activated Carbon” (E-AC) as a Supporting andProtective Porous Backbone for a Phthalocyanine Compound

Activated carbon (AC, from Ashbury Carbon Co.) was treated with an acidsolution (sulfuric acid, nitric acid, and potassium permanganate at aratio of 4:1:0.05) for 24 hours. Upon completion of the reaction, themixture was poured into deionized water and filtered. The treated AC wasrepeatedly washed in a 5% solution of HCl to remove most of the sulphateions. The sample was then washed repeatedly with deionized water untilthe pH of the filtrate was neutral. The slurry was then dried in avacuum oven pre-set at 70° C. for 24 hours. The dried sample was thenplaced in a tube furnace at 1,050° C. for 2 minutes to obtain expandedAC. This material can be used in both the anode and cathode of a lithiumcell due to its high specific surface area and ability to capture andstore Li atoms on its surfaces. These surfaces were also found to beparticularly suitable for supporting both metal and metal-freephthalocyanine compounds that are themselves lithium-storing materials.

Example 6 Chemically Treated (Expanded) Needle Coke as a Supporting andProtective Porous Backbone for a Phthalocyanine Compound

Anisotropic needle coke has a fully developed needle-shape texture ofoptical anisotropy. Volatile species of the raw coke was estimated to bearound 5 wt. %. Activation was carried out using KOH in a reactionapparatus that consisted of a stainless steel tube and a nickel sampleholder. KOH activation was carried out at 800° C. for 2 h under Ar flow.The coke/KOH ratio was varied between 1/1 and 1/4. Upon cooling, thealkali-rich coke was washed with hot water until the outlet waterreached a pH value of 7. The resulting chemically etched or expandedcoke was dried by heating at 60° C. in a vacuum for 24 hours. Thetreated coke is highly porous, having a pore size range of approximately1-85 nm.

Example 7 Chemically Treated (Expanded) Petroleum Pitch-Derived HardCarbon as a Supporting and Protective Porous Backbone for aPhthalocyanine Compound

A pitch sample (A-500 from Ashland Chemical Co.) was carbonized in atube furnace at 900° C. for 2 hours, followed by further carbonizationat 1,200° C. for 4 hours. KOH activation was carried out at 800° C. for2 h under Ar flow to open up the internal structure of pitch-based hardcarbon particles. The hard carbon-based porous structure was found tohave a particle size range of 3-100 nm and to be particularly suitablefor supporting and protecting both metal and metal-free phthalocyaninecompounds lodged therein.

Example 8 Chemically Activated Meso-Phase Carbon and Production ofFluorinated Carbon as a Conductive Substrate and Protective PorousBackbone for a Phthalocyanine Compound

Meso-carbon carbon particles (un-graphitized MCMBs) were supplied fromChina Steel Chemical Co. This material has a density of about 2.2 g/cm³with a median particle size of about 16 μm. This batch of meso-phasecarbon was divided into two samples. One sample was immersed in K₂CO₃ at900° C. for 1 h to form chemically activated meso-carbon. The chemicallyactivated meso-phase carbons showed a BET specific surface area of 1,420m²/g. This material can be used in both the anode and cathode due to itshigh specific surface area and ability to capture and store metal atomson its surfaces. These surfaces were found to be particularly suitablefor supporting and protecting both metal and metal-free phthalocyaninecompounds.

The other sample was subjected to a fluorination treatment. Themeso-phase carbon particles were mixed with a PVDF binder in a NMPsolution and coated onto an Al foil to form an electrode sheet. Thiselectrode sheet was used as a working electrode in an electrochemicalfluorination treatment apparatus consisting of a PTFE beaker, a Pt platecounter electrode, a Pd wire as a reference electrode, and (C₂H₅)₃N-3HFas electrolyte. The fluorination procedure was carried out at roomtemperature by potential sweeping from −1.0 V to 1.0 V at a 20 mV/s scanrate. X-ray diffraction data indicate that the inter-graphene spacinghas been increased from 0.337 nm to 0.723 nm.

Example 9 Graphitic Fibrils from Pitch-Based Carbon Fibers for Forming aPorous Backbone for a Phthalocyanine Compound

Fifty grams of graphite fibers from Amoco (P-55S) were intercalated witha mixture of sulfuric acid, nitric acid, and potassium permanganate at aweight ratio of 4:1:0.05 (graphite-to-intercalate ratio of 1:3) for 24hours. Upon completion of the intercalation reaction, the mixture waspoured into deionized water and filtered. The sample was then washedwith 5% HCl solution to remove most of the sulfate ions and residualsalt and then repeatedly rinsed with deionized water until the pH of thefiltrate was approximately 5. The dried sample was then exposed to aheat shock treatment at 950° C. for 45 seconds. The sample was thensubmitted to a mechanical shearing treatment in a Cowles (arotating-blade dissolver/disperser) for 10 minutes. The resultinggraphitic fibrils were examined using SEM and TEM and their length anddiameter were measured. Graphitic fibrils, alone or in combination withanother particulate carbon/graphite material, can be packed into ameso-porous structure for supporting both metal and metal-freephthalocyanine compounds.

Example 10 Expanded Multi-Walled Carbon Nanotubes (MWCNTs) as aConductive Substrate and Protective Porous Backbone for a PhthalocyanineCompound

Fifty grams of MWCNTs were chemically treated (intercalated and/oroxidized) with a mixture of sulfuric acid, nitric acid, and potassiumpermanganate at a weight ratio of 4:1:0.05 (graphite-to-intercalateratio of 1:3) for 48 hours. Upon completion of the intercalationreaction, the mixture was poured into deionized water and filtered. Thesample was then washed with 5% HCl solution to remove most of thesulfate ions and residual salt and then repeatedly rinsed with deionizedwater until the pH of the filtrate was approximately 5. The dried samplewas then exposed to a heat shock treatment at 950° C. for 45 seconds.Expanded MWCNTs, alone or in combination with another particulatecarbon/graphite material, can be packed into a meso-porous structure forsupporting both metal and metal-free phthalocyanine compounds.

Example 11 Preparation of a Metal-Free Naphthalocyanine-Graphene OxideHybrid Cathode

The starting material, 2,11,20,29-Tetra-tert-butyl-2,3-naphthalocyanine(NPc), was purchased from Aldrich. The graphene oxide used was preparedin Example 2. NPc chloroform solution (9.90×10³ mg/mL) was first mixedwith GO-chloroform solution at several concentrations (from 0 to1.64×10⁻³ mg/mL), and then sonicated for 15 min and centrifuged at 3000rpm for 30 min. The supernatants were characterized by SEM, TEM, AFM,X-ray diffraction, and absorption and fluorescence spectroscopy.Graphene oxide (GO) has a large 2D planar structure and its extended,delocalized π-electron system is expected to facilitate interaction withNPc through the π-π stacking. In order to ensure sufficient interactionsbetween them, a dilute NPc solution was first used because Pc moleculestend to aggregate at a high concentration. Then a series ofconcentrations of GO were chosen to interact with NPc and the resultanthybrid materials were monitored by the absorption and fluorescencespectra.

Comparative Example 11a and 11b

Preparation of a Metal-Free Naphthalocyanine-Acetylene Black HybridCathode and a Metal-Free Naphthalocyanine-GO Hybrid Cathode (without π-πBonding)

As a control sample, we have also prepared a hybrid material fromacetylene black (AB) and GO. The procedure was similar to that for theNPc/GO, but the GO-chloroform solution was replaced by an AB-chloroformsuspension.

NPc-GO hybrid samples were also prepared via a grinding and ball-millingprocedure, without using the co-precipitation from co-solvent as inExample 11 above. The GO sheets are used for the primary purpose ofproviding a 3D network of electron-conducting paths. There is asignificantly lower level of π-π bonding between NPc and GO in thesecontrol samples.

The cathode specific capacities of a series of composite cathodes madeup of 2,11,20,29-Tetra-tert-butyl-2,3-naphthalocyanine (NPc) andacetylene black (AB) were measured using a coin cell configurationcontaining lithium metal foil as the anode active material. The data,obtained from galvanostatic charge/discharge cycling tests, were plottedas a function of the NPC proportion at the cathode (NPc/[NPc+AB]) inFIG. 7(A). The corresponding data for NPc-GO cathodes were alsoincluded. It may be noted that the specific capacity of this GOmaterial, when used alone without NPc, is 243 mAh/g and that of NPcwithout any conductive additive is 118 mAh/g (although the theoreticallithium storage capacity of NPc is estimated to be at approximately 800mAh/g provided that every available NPC site is utilized). These datahave demonstrated that there exists a highly significant (actually quitedramatic) synergistic effect between NPc and this graphene material. Thespecific capacity values of 1137, 1547, and 1750 mAh/g (based on theNPc, GO, and binder weights combined, not just the NPc weight) arehigher than the very best values of all cathode active materials everreported for Li metal or Li-ion secondary cells.

The cycling performance of the cell featuring a cathode of chemicallybonded NPc-GO hybrid through the π-π bonding and that of the controlsample with a much lower level of π-π bonding between NPc and GO areshown in FIG. 7(C). Clearly, the cell containing a cathode with weakeror no π-π bonding exhibits a significantly higher decay rate ascharge/discharge cycles proceed. After 100 charge/discharge cycles, thetest was interrupted and the cell was opened with the cathode removedand measured. The cathode was found to have suffered some weight loss,likely indicating the dissolution of the active material (NPc) in theliquid electrolyte. In contrast, the strong π-π bonding between NPc andGO has prevented NPc from dissolving in the electrolyte, or from simplydetaching off from the GO substrate, to a much smaller extent.

In order to further verify if this synergistic effect occurs in metalnaphthalocyanine-graphene combinations, we proceeded to investigate thecathodes based on manganese naphthalocyanine (MnPc)-graphene and otherhybrid cathodes as well. The results, summarized in FIG. 7(B), areequally surprising and even more impressive. A cathode specific capacityof 2,116 mAh/g is absolutely unprecedented. It is of significance topoint out again that the graphene material used in this series of hybridmaterials only provides a maximum specific capacity of 243 mAh/g whenused alone. Further, the theoretical specific capacity of MnPc isapproximately 1,700 mAh/g (based on the MnPc weight alone). The capacityof 2,116 mAh/g could not have been anticipated by any prior artteaching, alone or in combination with other teaching.

By replacing graphene with a chemically activated MCMB material (poresize of approximately 4-35 nm), we have also observed a significantsynergistic effect, as also indicated in FIG. 7(B). The specificcapacity values of MnPc/A-MCMB cathodes are not as high as those ofMnPc/graphene when the A-MCMB proportion is lower than 50%. However, thetrend is reversed when the A-MCMB proportion is higher than 50% byweight, providing outstanding specific capacity. This observationfurther demonstrates that the meso-porous carbon/graphite materialsproduced by chemical activation, when used as a host to allow anaphthalocyanine compound to lodge in its pores, surprisingly bring outa synergistic effect in terms of the lithium storage capacity.

Example 12 Preparation of a Metal Phthalocyanine-Reduced Graphene Oxide(RGO) Hybrid Cathode

A suspension of single-layer GO sheets dispersed in water was firstprepared. To this GO suspension was added water-soluble tetrasulfonatesalt of copper phthalocyanine (TSCuPc). The resulting hybrid suspensionwas then subjected to a chemical reduction treatment to convert GO toRGO in the presence of TSCuPc. Specifically, the TSCuPc-RGO hybridmaterials were successfully prepared according to the following typicalprocedure: 10 mg of GO was dispersed in 10 mL of deionized water (DIwater) by ultrasonication for 30 min using a cup-horn ultrasonicator (16W power) to generate a homogeneous brown solution. The solution wascentrifuged for 15 min at 5000 rpm to remove a small amount ofaggregates. 10 mL of GO solution (1 mg/mL) was mixed with 25 mL of 0.01M TSCuPc aqueous solution in a round-bottom flask with a magneticstirring bar and a water-cooled condenser. Hydrazine hydrate(Sigma-Aldrich, St. Louis, Mo.) was added as a chemical reducing agent,and the solution was heated at 90° C. for 1 h under stirring. The colorof the solution changed from dark blue to dark green. The resultingsolution contained reduced single-layer graphene oxide sheets asconfirmed by AFM images. A dilute hybrid aqueous solution wasspin-coated onto a glass substrate and left overnight to evaporate thewater and was used for AFM measurement. UV-vis absorption spectra of thethin films of TSCuPc and RGO/TSCuPc hybrid materials were also obtained.It is believed that the chemical bonding between TSCuPc and GO or RGO isdominated by the π-π interaction.

The specific capacity of this RGO/TSCuPc hybrid cathode material withstrong π-π bonding, obtained from a coin cell configuration with Limetal as the anode active material and 1 M LiClO₄ in propylene carbonate(PC) solution as the electrolyte, is plotted as a function of thecharge/discharge cycles, FIG. 11(A).

A baseline sample of TSCuPc with 50% by weight of AB as the conductiveadditive was also prepared in a similar manner. Another baseline cellhaving a TSCuPc/RGO hybrid cathode with weak or no π-π bonding was alsoprepared through simple powder blending. The charge/discharge behaviorsof these cells were also monitored with the specific capacity data alsoincluded in FIG. 11(A). These data have clearly demonstrated that theCuPc-AB composite cathode has a fast capacity decay rate with thespecific capacity dropping to an unacceptably low value in less than 100cycles. In contrast, the graphene-enabled hybrid system with strong π-πbonding exhibits a minimal capacity decay even after 1000 cycles. Thecell with a TSCuPc/RGO hybrid cathode with weak or no π-π bonding has adecay rate lower than that of the CuPc-AB composite, but higher thanthat of the cell with a TSCuPc/RGO hybrid cathode with strong π-πbonding. This has further demonstrated the significance of chemicalbonding in reducing the cell capacity decay during repeatedcharges/discharges.

By replacing RGO with a meso-porous hard carbon (pore size 3-11 nm)produced by chemical expansion and activation of a hard carbon material,we prepared and tested a CuPc-E-HC cell. The specific capacity of thismeso-porous carbon cell is generally lower than that of the RGO-basedcell, but the cycling stability is better in comparison with TSCuPc/RGOhybrid cathode having no π-π bonding, as shown in FIG. 11(A) and FIG.11(B). Clearly, the problems associated with naphthalocyanine solubilityand its catalytic effect on electrolyte decomposition has been overcomeby implementing a reduced graphene oxide with strong chemical bonding ormeso-porous carbon structure as a host for the naphthalocyaninecompound. This discovery has not been taught and could not have beenanticipated by any prior art teaching.

Example 13 Preparation of Transition Metal Naphthalocyanine-GrapheneHybrid Cathode Materials Through Vapor Deposition

An iron naphthalocyanine (FePc) powder sample was placed in one end(sealed end or source end, at a higher temperature of 600° C.) of theinner quartz tube of a two-tube furnace system and a pristine graphenesample was placed at the opposite end (open end, at a lower temperatureof 200° C.). A stream of nitrogen was introduced into the space betweenthe inner tube and the outer tube at a flow rate of 50 cm³/min. The FePcwas sublimed with the vapor condensed and deposited onto surfaces ofgraphene sheets placed downstream from the source end. The ratio betweenFePc and graphene was varied by adjusting the deposition time, from 0.5hours to 5 hours. On a separate basis, a meso-porous soft carbon wasprepared and then iron naphthalocyanine was sublimed and deposit intopores of this chemically activated soft carbon.

Example 14 Preparation of Transition Metal Naphthalocyanine-Graphene orGraphene Oxide Hybrid Cathode Materials Through Co-Precipitation from aLiquid Solution and/or Suspension

Portion of the pristine graphene prepared in Example 3 was re-dispersed(partially dissolved) in NMP with the assistance of ultrasonication.Several cobalt naphthalocyanine (CoPc)/NMP solutions with different CoPcconcentrations were also prepared. The graphene/NMP solution andCoPc/NMP solution were then mixed to obtain a precursor hybrid solution,which was then dried by removing a majority of NMP by heat in a chemicalfume hood to form a slurry. Portion of the slurry was then cast onto aglass surface and the remaining portion was spray-dried to formsecondary particulates that contain CoPc primary particles (20-85 nm)and graphene sheets, with some graphene sheets embracing and wrappingaround CoPc particles (e.g. a SEM image of the secondary particulates isshown in FIG. 8).

We have observed that the secondary particulates of graphene-wrappednaphthalocyanine compound particles typically exhibit an electricalconductivity much greater than 10⁻⁴ S/cm, more typically greater than10⁻² S/cm when the graphene content exceeds 5% by weight, much greaterthan 1 S/cm when the graphene content exceeds 10%, and even greater than100 S/cm when the graphene content exceeds 20%.

In order to further explore the feasibility and advantages of chemicalbonding between a transition metal naphthalocyanine compound and agraphene material on the long-term cycling stability of the resultingbattery, a CoPc-bonded graphene hybrid material was prepared using asolid-phase synthesis method. For instance, a mixture of 0.25 g GOpowder, 0.60 g phthalic anhydride acid, 1.00 g urea, 0.50 g CoCl₂.6H₂O,0.75 g NH₄Cl and 0.10 g (NH₄)₂Mo₂O₇ was ground and ball-milled.Subsequently, the mixture was transferred into a 100 ml crucible, heatedin a muffle furnace at 140° C. for 1.5 h and subsequently at 270° C. for3 h. Upon cooling to room temperature, the product was washed and rinsedwith water, acetone, and methyl alcohol. The precipitates were driedunder vacuum at 60° C. overnight.

The same procedure was also applied to other conductive substratematerials, including activated carbon (AC) and chemically treated MCMB,to obtain CoPc-bonded AC and MCMB, for instance. A reference CoPc wasalso synthesized under the same condition but without the presence of GOsheets, AC, or MCMB.

The specific capacity values of a CoPc-bonded graphene cathode and acorresponding CoPc/graphene hybrid (without bonding) are plotted as afunction of the charge/discharge cycle number in FIG. 13(A). Similarly,the specific capacity values of a CoPc-bonded MCMB cathode (MCMBchemically activated and porous) and a corresponding CoPc/MCMB hybrid(without bonding), plotted as a function of charge/discharge cyclenumber, are summarized in FIG. 13(B). These data have also clearlydemonstrated the significance of chemical bonding in holding anaphthalocyanine compound to a conductive substrate to avoid dissolutionof the active compound in the electrolyte. Such a strategy again enablesa rechargeable lithium battery to maintain its high lithium storagecapacity during repeated charges/discharges.

Example 15 Preparation of Metal Phthalocyanine-Graphene Hybrid CathodeMaterials Through Hydrogen Bonding

The iron (II) octacarboxyphthalocyanine (FeOCPc, its chemical formulabeing schematically shown in FIG. 2(D)) was prepared with a proceduredescribed below: Briefly, in a two-neck flask equipped with a refluxcondenser and a thermometer was added 2.50 g (11.5 mmol) of pyromelliticdianhydride, 13.0 g (0.22 mmol) of urea, 23.5 mmol of FeCl₂, and 0.1 g(0.65 mmol) of 1,8-diazacyclo[5.4.0]undec-7-ene (DBU). The flask washeated to 250° C. until the reaction mixture was fused. The reactionproduct was washed with water, acetone and 6 M hydrochloric acid (HCl).After being dried, the solid obtained was hydrolyzed. 30 g of crudeproduct, 30 g of potassium hydroxide (KOH) and 90 mL of water werecharged into a 300 mL beaker. The beaker was heated for 480 min at 100°C. The mixture was diluted with 200 mL water and was filtered. Thefiltrate was acidified to pH 2 with concentrated HCl. The productprecipitated as a green solid at this point. The green product wasseparated from the solution by a centrifuge. The solid was furtherdissolved in NaOH and subjected to column chromatography using aluminabed with NaOH solution as an eluant. The eluant was acidified as beforeto precipitate the solid product via centrifugation and dried. The yieldwas found to be approximately 30%. For C₈₈H₁₂₈N₈H₁₆Fe, the chemicalcomposition is calculated to be: C, 70.87; H, 8.63; N, 7.51%. What wasexperimentally found: C, 70.18; H, 8.40; N, 7.43%. λ_(max)(pyridine)/nm: 684.0. ν_(max)/cm⁻¹: 3300 (νC—H), 2900 (νC—H), 1590(νC—C), 1150 (νC—C), 1150 (δC—O), 1090 (δC—H).

In a typical procedure of preparing a hydrogen bonded metalphthalocyanine-graphene hybrid cathode material through hydrogenbonding, 0.25 mg of graphene oxide (GO) and 0.75 mg of FeOCPc weredispersed in 1 mL deionized water with the aid of ultrasonic stirring.15 mL of the resulting suspension was cast onto the surface of a glassplate and allowed to dry at room temperature to prepare thehydrogen-bonded FeOCPc-GO hybrid material.

Comparative Example 15a Preparation of Metal Phthalocyanine-GrapheneHybrid Cathode Materials Through Simple Powder Blending (No or WeakHydrogen Bonding)

In a typical procedure, a mixture of FeOCPc and GO powder with acontrolled weight ratio (typically from 1/4 to 1/1) was hand-ground in amortar by pestle for 20 minutes to 1 hour. Portion of the powder mixturewas then ball-milled for 1-3 hours.

The specific capacity values of a hydrogen-bonded FeOCPc/graphenecathode and a corresponding FeOCPc/graphene hybrid (without bonding) areplotted as a function of the charge/discharge cycle number in FIG. 14.These data have clearly demonstrated the significance of chemicalbonding (hydrogen bond in this case) in holding a naphthalocyaninecompound to a conductive substrate to avoid dissolution of the activecompound in the electrolyte. Such a strategy again enables arechargeable lithium battery to maintain its high lithium storagecapacity during repeated charges/discharges.

Example 16 Meso-Porous Soft Carbon as an Anode Active Material

Chemically etched or expanded soft carbon was prepared from a liquidcrystalline aromatic resin. The resin was ground with a mortar, andcalcined at 900° C. for 2 h in a N₂ atmosphere to prepare thegraphitizable carbon or soft carbon. The resulting soft carbon was mixedwith small tablets of KOH (four-fold weight) in an alumina melting pot.Subsequently, the soft carbon containing KOH was heated at 750° C. for 2h in N₂. Upon cooling, the alkali-rich residual carbon was washed withhot water until the outlet water reached a pH value of 7. The resultingchemically etched or expanded soft carbon was dried by heating at 60° C.in a vacuum for 24 hours. The high surface areas are available tocapture and store lithium when a cell is recharged. With these surfaces,the re-deposited lithium layer appears to be more stable with respect tothe electrolyte as compared to a bare current collector, such as copperfoil alone.

Example 17 Expanded Activated Carbon (E-AC) as an Anode Active Material

Activated carbon (AC, from Ashbury Carbon Co.) was treated with an acidsolution (sulfuric acid, nitric acid, and potassium permanganate at aratio of 4:1:0.05) for 24 hours. Upon completion of the reaction, themixture was poured into deionized water and filtered. The treated AC wasrepeatedly washed in a 5% solution of HCl to remove most of the sulphateions. The sample was then washed repeatedly with deionized water untilthe pH of the filtrate was neutral. The slurry was then dried in avacuum oven pre-set at 70° C. for 24 hours. The dried sample was thenplaced in a tube furnace at 1,050° C. for 2 minutes to obtain expandedAC.

Example 18 Chemically Treated Needle Coke as an Anode Active Material

Anisotropic needle coke has a fully developed needle-shape texture ofoptical anisotropy. Volatile species of the raw coke was estimated to bearound 5 wt. %. Activation was carried out using KOH in a reactionapparatus that consisted of a stainless steel tube and a nickel sampleholder. KOH activation was carried out at 800° C. for 2 h under Ar flow.The coke/KOH ratio was varied between 1/1 and 1/4. Upon cooling, thealkali-rich coke was washed with hot water until the outlet waterreached a pH value of 7. The resulting chemically etched or expandedcoke was dried by heating at 60° C. in a vacuum for 24 hours.

Example 19 Chemically Treated Petroleum Pitch-Derived Hard Carbon as anAnode Active Material

A pitch sample (A-500 from Ashland Chemical Co.) was carbonized in atube furnace at 900° C. for 2 hours, followed by further carbonizationat 1,200° C. for 4 hours. KOH activation was carried out at 800° C. for2 h under Ar flow to open up the internal structure of pitch-based hardcarbon particles.

Example 20 Chemically Expanded Meso-Phase Carbon as an Anode ActiveMaterial

Meso-carbon micro-beads (MCMBs) were supplied from China Steel ChemicalCo. This material has a density of about 2.24 g/cm³ with a medianparticle size of about 16 μm. The MCMB powder was immersed in K₂CO₃ at900° C. for 1 h. The chemically treated meso-phase carbons showed a BETspecific surface area of 1,420 m²/g.

Example 21 Graphitic Fibrils from Pitch-Based Carbon Fibers as an AnodeActive Material

Fifty grams of graphite fibers from Amoco (P-55S) were intercalated witha mixture of sulfuric acid, nitric acid, and potassium permanganate at aweight ratio of 4:1:0.05 (graphite-to-intercalate ratio of 1:3) for 24hours. Upon completion of the intercalation reaction, the mixture waspoured into deionized water and filtered. The sample was then washedwith 5% HCl solution to remove most of the sulfate ions and residualsalt and then repeatedly rinsed with deionized water until the pH of thefiltrate was approximately 5. The dried sample was then exposed to aheat shock treatment at 950° C. for 45 seconds. The sample was thensubmitted to a mechanical shearing treatment in a Cowles (arotating-blade dissolver/disperser) for 10 minutes. The resultinggraphitic fibrils were examined using SEM and TEM and their length anddiameter were measured.

Example 22 Expanded Multi-Walled Carbon Nanotubes (MWCNTs) as an AnodeActive Material

Fifty grams of MWCNTs were chemically treated (intercalated and/oroxidized) with a mixture of sulfuric acid, nitric acid, and potassiumpermanganate at a weight ratio of 4:1:0.05 (graphite-to-intercalateratio of 1:3) for 48 hours. Upon completion of the intercalationreaction, the mixture was poured into deionized water and filtered. Thesample was then washed with 5% HCl solution to remove most of thesulfate ions and residual salt and then repeatedly rinsed with deionizedwater until the pH of the filtrate was approximately 5. The dried samplewas then exposed to a heat shock treatment at 950° C. for 45 seconds.

Example 23 Prelithiated and Non-Lithiated Nano Cobalt Oxide (Co₃O₄)Anodes

An appropriate amount of inorganic salts Co(NO₃)₂.6H₂O was added to anammonia solution (NH₃.H₂O, 25 wt %). The resulting precursor suspensionwas stirred for 4 hours under an argon flow condition to ensure acomplete reaction. The resulting Co(OH)₂ precursor suspension wasfiltered and dried under vacuum at 70° C. to obtain a Co(OH)₂. Thisprecursor was calcined at 450° C. in air for 2 h to form nano Co₃O₄powder with an average particle size of approximately 34 nm.

The working electrodes (for use as an anode in a lithium-ion cell) wereprepared by mixing 85 wt % active material (Co₃O₄ powder), 7 wt %acetylene black (Super-P), and 8 wt % polyvinylidene fluoride (PVDF, 5wt % solid content) binder dissolved in N-methyl-2-pyrrolidinoe (NMP) toform a slurry-like mixture. After coating the slurry on Cu foil, theelectrode was dried at 120° C. in vacuum for 2 h to remove the solventbefore pressing. The electrode prepared was divided into two pieces: onepiece was for use as a non-prelithiated anode and the other piece wasprelithiated electrochemically by following the procedure describedbelow:

The second piece of Co₃O₄ electrode was immersed in a liquid electrolyteprepared by dissolving 1 M LiPF₆ electrolyte solution in a mixture ofethylene carbonate (EC) and diethyl carbonate (DEC) (EC-DEC, 1:1 v/v). Apiece of lithium foil was used as a counter-electrode, which was alsoimmersed in the electrolyte. Direct current was used to charge the Co₃O₄electrode until an amount of lithium equivalent to approximately 860mAh/g based on cobalt oxide weight was inserted into Co₃O₄. Theprelithiation procedure was performed in an argon-filled glove-box.

Subsequently, the lithiated and non-lithiated electrodes were separatelycut into disks (diameter=12 mm) for use as an anode. In the cellcontaining a non-lithiated Co₃O₄ anode, a thin sheet of lithium foil (asa lithium source) was attached to the anode surface and a piece ofporous separator was, in turn, stacked on top of the lithium foil.Pieces of electrodes prepared from the iron naphthalocyanine(FePc)-graphene of Example 6 and coated on an aluminum foil (cathodecurrent collector) were used as a cathode to form a CR2032 coin-typecell. Celgard 2400 membrane was used as separator, and 1 M LiPF₆electrolyte solution dissolved in a mixture of ethylene carbonate (EC)and diethyl carbonate (DEC) (EC-DEC, 1:1 v/v) was used as cellelectrolyte. The cell assembly was performed in an argon-filledglove-box. The CV measurements were carried out using a CHI-6electrochemical workstation at a scanning rate of 1 mV/s.

Comparative Example 23

Li-Ion Cells Containing a Prelithiated or Non-Lithiated Nano CobaltOxide (Co₃O₄) Anode and a Lithium Iron Phosphate Cathode

Lithium iron phosphate LiFePO₄ is a promising candidate cathode materialin lithium-ion batteries for electric vehicle applications. Theadvantages of LiFePO₄ as a cathode active material includes a hightheoretical capacity (170 mAh/g), environmental benignity, low resourcecost, good cycling stability, high temperature capability, and prospectfor a safer cell compared with LiCoO₂. For comparison purposes, we havealso prepared similar Li-ion cells containing LiFePO₄ as the cathodeactive material.

The electrochemical performance of the prelithiated Co₃O₄anode/FePc-graphene cell (pore size of graphene cathode=11-71 nm),pre-lithiated Co₃O₄/FePc-meso-graphene cell (graphene cathode poresize=4-12 nm), lithiated Co₃O₄/LiFePO₄ cell, and non-lithiatedCo₃O₄/LiFePO₄ cell was also evaluated by galvanostatic charge/dischargecycling at a current density of 50 mA/g, using a LAND electrochemicalworkstation.

The Ragone plots of five types of electrochemical cells are presented inFIG. 9. These data have demonstrated that the presently invented Li-ioncells using FePc-graphene hybrid as a cathode active material exhibitexceptional energy density and relatively good power density. Both ofthe new cells (both having a pre-lithiated Co₃O₄ anode active materialand graphene-FePc hybrid cathode) have an energy density higher than 300Wh/kg, which is significantly greater than the typical 120-150 Wh/kg ofprior art lithium-ion cells. Most surprisingly, these cells can alsodeliver a power density that is 10 times higher than those of prior artLi-ion cells (typically <0.5 kW/kg). The power density of the new cellreaches 6.7 kW/kg, which has never been achieved with any prior artlithium-ion cells. The implementation of a hybrid FePc-graphene materialas a cathode active material has made it possible to achieve both highenergy density and high power density.

As a point of reference, the typical power density of symmetricsupercapacitors (noted for their superior power density) is 3-6 kW/kg;but their energy density is 5-8 Wh/kg. The presently invented Li-ioncells have achieved both high energy density and high power density thatcannot be achieved with current supercapacitors or lithium-ionbatteries.

For comparison purposes, the Ragone plot of a Li-ion cell containing aprelithiated Co₃O₄ anode and a composite cathode made of FePc (50% byweight) and acetylene black (50% AB) is also included in FIG. 9.Clearly, this very best member of the series of FePc-AB based cells doesnot even come close to the FePc-graphene based cells in terms of bothenergy density and power density (rate capability).

Another unexpected result comes from a comparison between porousgraphene/FePc hybrid (graphene structure having a pore size range of11-71 nm) and a meso-porous graphene/FePc hybrid (meso-porous graphenestructure having a pore size range of 4-12 nm). The meso-porousstructure gives rise to a higher energy density and higher powerdensity. The reasons for such a difference remain to be investigated.

Example 24 Li-Ion Cells Having a Prelithiated Tin Oxide Anode and aBall-Milled NiPc-RGO Cathode or a Chemically-Bonded NiPc-RCO Cathode

Tin oxide (SnO₂) nano particles were obtained by the controlledhydrolysis of SnCl₄.5H₂O with NaOH using the following procedure:SnCl₄.5H₂O (0.95 g, 2.7 m-mol) and NaOH (0.212 g, 5.3 m-mol) weredissolved in 50 mL of distilled water each. The NaOH solution was addeddrop-wise under vigorous stirring to the tin chloride solution at a rateof 1 mL/min. This solution was homogenized by sonication for 5 min. Thissolution was divided into two portions. One portion of the resultinghydrosol was reacted with a graphene oxide dispersion supplied byAngstron Materials, Inc. (Dayton, Ohio) for 3 hours and the otherportion was not mixed with graphene oxide.

To this graphene oxide mixed solution and un-mixed solution separately,few drops of 0.1 M of H₂SO₄ were added to flocculate the product. Theprecipitated solid was collected by centrifugation, washed with waterand ethanol, and dried in vacuum. The dried product was heat-treated at400° C. for 2 h under Ar atmosphere. The graphene oxide-assisted samplewas found to contain mostly nano-scaled tin oxide particles with anaverage particle size of 27 nm. The presence of graphene oxide serves toregulate the nucleation and growth of tin oxide crystals, promoting theformation of nano particles. The other sample contains sub-micron andmicron-scaled tin oxide particles with an average diameter >1.3 μm.

The battery cells from the graphene oxide-regulated particulates(containing nano-scaled SnO₂) and the micron-scaled SnO₂ particles(having acetylene black particles as a conductive filler) were preparedusing a procedure described in Example 23. The tin oxide waselectrochemically prelithiated up to a specific capacity ofapproximately 1,200 mAh/g. The testing methods were also similar tothose used in Example 23.

The chemically-bonded NiPc-RCO cathode was prepared in a manner similarto that described in Example 14, but with Co being replaced by Ni.

Comparative Example 24B

Prelithiated Tin Oxide as the Anode Active Material and Ball-MilledNiPc-AC Composite as the Cathode Active Material in a ConventionalLi-Ion Cell

For comparison purposes, we have also prepared a correspondinglithium-ion cell containing prelithiated tin oxide as the anode activematerial and ball-milled NiPc-AC as the cathode active material(AC=activated carbon). We also proceeded to chemically expand/exfoliatesome AC to obtain meso-porous AC, which was used to accommodate NiPc foryet another cell.

Presented in FIG. 10 are the Ragone plots of four types ofelectrochemical cells. Two of the cells represent two examples of thepresently invented NiPc-RGO cathode-based Li-ion cells: one containingnon-lithiated SnO₂ nano particles as an anode active material and Lifoil as a lithium ion source and the other containing prelithiated SnO₂micron particles as an anode active material. In both cases, the SnO₂particles were bonded to the anode current collector with a resinbinder, along with a conductive additive. The cell with nano-scaled SnO₂anode particles exhibits a higher energy density as compared with itsmicron-scale SnO₂ counterpart. These two cells exhibit an exceptionallyhigh energy density (>400 Wh/kg), which is significantly greater thanthose of corresponding Li-ion cell (using prelithiated SnO₂ as the anodeactive material and NiPc-AC as a cathode active material). There hasbeen no cathode material thus far reported in the prior art that couldenable a lithium-ion cell containing an anode to exhibit an energydensity higher than 300 Wh/kg. This is clearly a very impressive andunexpected result.

When chemically expanded/exfoliated AC (meso-AC) was used to support andprotect NiPc in the cathode, the energy density and power density of thecell were significantly improved. This further demonstrates theimportance of having a meso-porous structure at the cathode.

We further conducted a dissolution experiment by simply dispersing theintended cathode active material in an intended liquid electrolyte (1 MLiPF₆ electrolyte solution in a mixture of ethylene carbonate (EC) anddiethyl carbonate (DEC) with a EC-DEC ratio of 1:1 v/v) for 24 hours.The cathode material was then recovered, dried, and weighed. It wasfound that the chemically-bonded NiPc-RCO experienced a weight loss ofapproximately 0.6%, but the simply blended NiPc-RCO (ball-milled)suffered a 5.5% weight loss after 24 hours. The cell featuring achemically-bonded NiPc-RCO cathode exhibits a much more stable cyclingbehavior.

Example 25 Prelithiated Si Nanowires as an Anode Active Material andMnPc-RGO or MnPc-E-SC (Expanded Soft Carbon) as a Cathode ActiveMaterial

In a typical procedure for preparing Si nanowires, approximately 2.112 gof silicon powders (average diameter 2.64 μm) were mixed with 80 ml of a0.1M aqueous solution of Ni(NO₃).6H₂O and vigorously stirred for 30 min.Then, water was evaporated in a rotary evaporator and the solid remnantswere completely dried in an oven at 150° C. The final sample(Ni-impregnated Si powers) was obtained by grinding the solids in amortar.

Subsequently, 0.03 g of Ni-impregnated Si particles was placed in aquartz boat, and the boat was placed in a tube furnace. The sample wasreduced at 500° C. for 4 hours under flowing Ar (180 sccm) and H₂ (20sccm); then the temperature was raised to 990° C. to synthesize Sinanowires. For the purpose of separating Si nanowires, for instance,every 0.1 g of the reacted Si powders was mixed with 10 ml of ethanoland the resulting mixture was sonicated for 1 hour. Subsequently, Sinanowires were separated from the Si powders by centrifuging at 5,000rpm for 10 min.

Si nanowires were mixed with acetylene black particles to prepareanodes. The electrodes made were lithiated by using a procedure similarto that described in Example 16. Coin cells were similarly made usingMnPc-RGO as the cathode active material, but three types of materialsseparately as the anode active material: (i) prelithiated Si nanowires,(ii) Li metal foil alone, and (iii) expanded MWCNTs with Li metal foil.

Coin cells using MnPc-RGO or MnPc-E-SC as a cathode active material(+10% PVDF as a resin binder) and the three anode active materials weremade and tested. In all cells, the separator used was one sheet ofmicro-porous membrane (Celgard 2500). The current collector for thecathode was a piece of carbon-coated aluminum foil and that for theanode was Cu foil. The electrolyte solution was 1 M LiPF₆ dissolved in amixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) with a3:7 volume ratio. The separator was wetted by a minimum amount ofelectrolyte to reduce the background current. Cyclic voltammetry andgalvanostatic measurements of the lithium cells were conducted using anArbin 32-channel supercapacitor-battery tester at room temperature (insome cases, at a temperature as low as −40° C. and as high as 60° C.).

The Ragone plots of the three types of electrochemical cells are shownin FIG. 12 One of the MnPc-RGO cathode-based Li cells of the presentinvention are capable of delivering a cell-level energy density greaterthan 600 Wh/kg, an unprecedented value of all lithium-ion cells everreported. The other two (one having a meso-porous E-SC supported MnPccathode) can store an energy density >400 Wh/g, a very impressive valueas well. These cells are also capable of delivering a power density of3-6 kW/kg, comparable to those of the best symmetric supercapacitors.The anode containing only the Li foil appear to deliver the best powerdensity; however, the cycling stability of this cell is not as good asthe other two cells that contain an intercalation compound as an anodeactive material.

Example 26 Preparation of Mono-Amino-Iron Phthalocyanine (MA-FePc) andMA-FePc-Bonded Reduced Graphene Oxide

To a flask, 4-nitrophthalonitrile, 4-tert-butylphthalonitrile, and ironchloride at a molar ratio of 1:3:4 were charged according to. Themixture was slowly heated to 165° C. and held for 3 hours. Upon coolingto room temperature, the mixture was dissolved in tetrahydrofuran (THF)and then hydrazine was added to reduce nitro group to amino group. Afterreduction, THF was removed by vacuum evaporation, and the mixture wasseparated on a silica gel column to give a pure product.

To 0.5% graphene oxide-water solution, solution of 3% mono-amino-ironphthalocyanine in isopropanol was slowly added. After addition ofmono-amino-iron phthalocyanine, the mixture was heated to 70° C. andheld for 6 hours before hydrazine was introduced. The mixture was heldat 70° C. for additional 8 hours. After the mixture was cooled to roomtemperature, solids were harvested via filtration. The solids werewashed with copious de-ionized water and dried in an oven at 120° C. for8 hours. TGA analysis indicates that ironphthalocyanine component is 20%in the FePc-bonded rGO composite.

We then conducted a dissolution experiment by simply dispersing theintended cathode active material in an intended liquid electrolyte (1 MLiPF₆ electrolyte solution in a mixture of ethylene carbonate (EC) anddiethyl carbonate (DEC) with a EC-DEC ratio of 1:1 v/v) for 24 hours.The cathode material was then recovered, dried, and weighed. It wasfound that the chemically-bonded MA-FePc-RCO experienced a weight lossof approximately 0.4%, but the simply blended MA-FePc-RCO (ball-milled)suffered a 4.7% weight loss after 24 hours. The battery cell featuring achemically-bonded FePc-RCO cathode exhibits a much more stable cyclingbehavior.

In summary, after extensive and in-depth studies, we have developed anew rechargeable lithium battery technology based on newelectrochemistry:

-   -   (1) We have discovered that a broad array of naphthalocyanine        compounds, when chemically bonded to a broad array of conductive        substrate materials (e.g. graphene, activated carbon, etc), can        be used as a cathode active material of a rechargeable lithium        cell (lithium metal secondary cell or lithium-ion cell). We have        further observed that these chemically bonded naphthalocyanine        hybrid materials can exhibit a stable specific capacity        significantly higher than 1,000 mAh/g and, in several samples,        the capacity has exceeded 2,000 mAh/g, after hundreds or        thousands of charge/discharge cycles. This has been most        surprising and has not been reported or predicted by those who        work in the battery industry or the field of electrochemistry.        All the commonly used cathode active materials for lithium-ion        cells have a practical specific capacity lower than 250 mAh/g        (mostly lower than 200 mAh/g).    -   (2) Chemical bonding between a naphthalocyanine compound and a        conductive substrate material appears to be effective in holding        the naphthalocyanine compound in the cathode, thereby preventing        significant dissolution in a liquid electrolyte and enabling a        stable battery cell cycling behavior.    -   (3) The implementation of a chemically bonded        naphthalocyanine-graphene hybrid material cathode in a        rechargeable lithium cell has led to an unprecedentedly high        energy density that is typically greater than 300 Wh/kg (based        on the total cell weight), often greater than 400 Wh/kg, and        even greater than 600 Wh/kg in several cases. This cell can be        charged and discharged for thousands of cycles with very little        capacity fade when adequate chemical bonding is imparted. This        can potentially have a revolutionary effect in ushering in a        vibrant electric vehicle industry. Current lithium batteries        have too low an energy density to provide an adequate EV driving        distance (e.g. >350 miles on one battery charge) without an        excessive battery weight. Current all-battery EVs capable of a        300-mile driving range have a battery pack weight of >900 kg.    -   (4) By chemically bonding a naphthalocyanine compound to a        conductive substrate, we have overcome several longstanding and        challenging technical issues that have thus far impeded the        commercialization of lithium secondary battery having a        naphthalocyanine compound-based cathode:        -   a. These cathode active materials are electrically            insulating and, hence, require the use of a large amount of            conductive additives (e.g. carbon black, CB, or acetylene            black, AB) that are electrochemically inactive materials            (not contributing to lithium storage, yet adding extra            weights to the cell). Typically, up to >50% by weight of            inactive materials has to be added. In contrast, a wide            range of conductive substrate material weight fractions,            small or large, can be used and, in all proportions except            for the case of <1% of graphene, the improvement has been            dramatic and synergistic.        -   b. It appears that the presence of a highly conductive            substrate material, such as graphene or MCMB, can            significantly reduce the dimensions of the naphthalocyanine            compound crystal, thereby reducing the required lithium            diffusion paths and increasing the lithium storing/releasing            rates. Somehow the presence of a naphthalocyanine compound            also enhances the lithium storage capacity of a graphene            material. In other words, the co-existence of both a            naphthalocyanine compound and a conductive material            unexpectedly lead to an exceptional cathode specific            capacity and cell energy density that cannot be achieved by            either component alone.        -   c. All the metal phthalocyanine compounds (MPc) have a            catalytic effect on decomposition of electrolytes, creating            cycle reversibility and long-term stability issues. The            chemical bonding with a conductive carbon/graphite material            appears to have alleviated or even eliminated these            problems. Not wishing to be bound by theory, but it is            further possible that the bonding between phthalocyanine and            a conductive nano carbon/graphite material has favorably            altered the chemical environment through charge transfer            between the two materials when in intimate contact with each            other, thereby significantly reducing the catalytic            interaction of phthalocyanine with the electrolyte phase.

We claim:
 1. A rechargeable lithium cell comprising: (a) An anodecomprising an anode active material; (b) A cathode comprising a hybridcathode active material composed of an electrically conductive substrateand a phthalocyanine compound chemically bonded to or immobilized bysaid conductive substrate, wherein said phthalocyanine compound is in anamount of from 1% to 99% by weight based on the total weight of theconductive substrate and the phthalocyanine compound combined; and (c)Electrolyte or a combination of electrolyte and a porous separator,wherein said separator is disposed between said anode and said cathodeand the electrolyte is in ionic contact with said anode and saidcathode.
 2. The rechargeable lithium cell of claim 1, wherein saidphthalocyanine compound is selected from copper phthalocyanine, zincphthalocyanine, tin phthalocyanine, iron phthalocyanine, leadphthalocyanine, nickel phthalocyanine, vanadyl phthalocyanine,fluorochromium phthalocyanine, magnesium phthalocyanine, manganousphthalocyanine, dilithium phthalocyanine, aluminum phthalocyaninechloride, cadmium phthalocyanine, chlorogallium phthalocyanine, cobaltphthalocyanine, silver phthalocyanine, a metal-free phthalocyanine, achemical derivative thereof, or a combination thereof.
 3. Therechargeable lithium cell of claim 1, wherein said anode active materialcontains a prelithiated lithium storage material or a combination of alithium storage material and a lithium ion source selected from lithiummetal, lithium alloy, or lithium-containing compound.
 4. Therechargeable lithium cell of claim 1, wherein said conductive substrateis made from a material selected from graphene, graphene oxide, reducedgraphene oxide, graphene fluoride, doped graphene, functionalizedgraphene, expanded graphite, exfoliated graphite or graphite worms,chemically etched or expanded soft carbon, chemically etched or expandedhard carbon, chemically functionalized activated carbon, chemicallyfunctionalized carbon black, chemically treated carbon nanotube,nitrogen-doped carbon nanotube, boron-doped carbon nanotube, chemicallydoped carbon nanotube, ion-implanted carbon nanotube, chemicallyfunctionalized carbon nano-fiber, chemically functionalized carbonfiber, chemically activated graphite fiber, chemically functionalizedcarbonized polymer fiber, chemically functionalized coke, chemicallyfunctionalized meso-phase carbon, chemically functionalized meso-porouscarbon, or a combination thereof.
 5. The rechargeable lithium cell ofclaim 1, wherein said phthalocyanine compound is chemically bonded tothe conductive substrate through a chemical bond selected from covalentbond, ionic bond, π-π interaction, hydrogen bond, coordinate bond, or acombination thereof.
 6. The rechargeable lithium cell of claim 5,wherein said chemical bond is accompanied or assisted by van der Waalsforces.
 7. The rechargeable lithium cell of claim 1, wherein saidconductive substrate is made from a material having a functional groupchemically bonded with said phthalocyanine compound.
 8. The rechargeablelithium cell of claim 3, wherein said substrate has a specific surfacearea greater than 100 m²/g when measured prior to chemically bonding tosaid phthalocyanine compound, or greater than 80 m²/g when measuredafter chemically bonding to said phthalocyanine compound.
 9. Therechargeable lithium cell of claim 3, wherein said substrate has aspecific surface area greater than 500 m²/g when measured prior tochemically bonding to said phthalocyanine compound, or greater than 400m²/g when measured after chemically bonding to said phthalocyaninecompound.
 10. The rechargeable lithium cell of claim 3, wherein saidsubstrate has a specific surface area greater than 1,000 m²/g whenmeasured prior to chemically bonding to said phthalocyanine compound, orgreater than 800 m²/g when measured after chemically bonding to saidphthalocyanine compound.
 11. The rechargeable lithium cell of claim 1,wherein said conductive substrate is made from a graphene materialselected from a single-layer sheet or multi-layer platelet of graphene,graphene oxide, fluorinated graphene, halogenated graphene, hydrogenatedgraphene, nitrogenated graphene, pristine graphene, doped graphene,boron doped graphene, nitrogen doped graphene, chemically treatedgraphene, reduced graphene oxide, functionalized graphene,functionalized graphene oxide, or a combination thereof.
 12. Therechargeable lithium cell of claim 1, wherein said conductive substratehas a meso-porous structure having a pore size in the range of 2 to 50nm.
 13. The rechargeable lithium cell of claim 1, wherein saidconductive substrate has a meso-porous structure having a pore size inthe range of 2 to 10 nm
 14. The rechargeable lithium cell of claim 1,wherein said conductive substrate is a porous material selected frommetal foam, carbon-coated metal foam, graphene-coated metal foam, metalweb or screen, carbon-coated metal web or screen, graphene-coated metalweb or screen, perforated metal sheet, carbon-coated porous metal sheet,graphene-coated porous metal sheet, metal fiber mat, carbon-coatedmetal-fiber mat, graphene-coated metal-fiber mat, metal nanowire mat,carbon-coated metal nanowire mat, graphene-coated metal nano-wire mat,surface-passivated porous metal, porous conductive polymer film,conductive polymer nano-fiber mat or paper, conductive polymer foam,carbon foam, carbon aerogel, carbon xerox gel, graphene foam, grapheneoxide foam, reduced graphene oxide foam, or a combination thereof. 15.The rechargeable lithium cell of claim 1, wherein said anode activematerial contains a lithium storage material selected from: (a) silicon(Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi),zinc (Zn), aluminum (Al), titanium (Ti), cobalt (Co), nickel (Ni),manganese (Mn), iron (Fe), cadmium (Cd), or a mixture thereof; (b) alloyor intermetallic compound of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Fe, Co,Ni, Mn, Cd, or a mixture thereof; (c) oxide, carbide, nitride, sulfide,phosphide, selenide, telluride, or antimonide of Si, Ge, Sn, Pb, Sb, Bi,Zn, Al, Fe, Ti, Co, Ni, Mn, Cd, or a mixture or composite thereof, (d)salt or hydroxide of Sn; or (e) a carbon or graphite material.
 16. Therechargeable lithium cell of claim 1, wherein phthalocyanine compound islodged in a pore or a plurality of pores of said conductive substrate toform a hybrid structure having an electrical conductivity no less than10⁻² S/cm.
 17. The rechargeable lithium cell of claim 16, wherein saidhybrid structure has an electrical conductivity greater than 1 S/cm. 18.The rechargeable lithium cell of claim 1, wherein phthalocyaninecompound is lodged in a pore or a plurality of pores of said conductivesubstrate to form a hybrid structure having a specific surface areagreater than 50 m²/g.
 19. The rechargeable lithium cell of claim 1,wherein phthalocyanine compound is lodged in a pore or a plurality ofpores of said conductive substrate to form a hybrid structure having aspecific surface area greater than 100 m²/g.
 20. The rechargeablelithium cell of claim 1, wherein phthalocyanine compound is lodged in apore or a plurality of pores of said conductive substrate and thephthalocyanine compound lodged in a pore has a dimension smaller than 20nm.
 21. The rechargeable lithium cell of claim 1, wherein phthalocyaninecompound is lodged in a pore or a plurality of pores of said conductivesubstrate and the phthalocyanine compound lodged in a pore has adimension smaller than 10 nm
 22. The rechargeable lithium cell of claim3, wherein said prelithiated lithium storage material is selected from:(a) a pre-lithiated silicon (Si), germanium (Ge), tin (Sn), lead (Pb),antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti),cobalt (Co), nickel (Ni), manganese (Mn), iron (Fe), cadmium (Cd), or amixture thereof; (b) a pre-lithiated alloy or intermetallic compound ofSi, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Fe, Co, Ni, Mn, Cd, or a mixturethereof; (c) a pre-lithiated oxide, carbide, nitride, sulfide,phosphide, selenide, telluride, or antimonide of Si, Ge, Sn, Pb, Sb, Bi,Zn, Al, Fe, Ti, Co, Ni, Mn, Cd, or a mixture or composite thereof, (d) apre-lithiated salt or hydroxide of Sn; or (e) a pre-lithiated carbon orgraphite material.
 23. The rechargeable lithium cell of claim 1, whereinthe lithium storage material is selected from graphite worms, exfoliatedgraphite flakes, expanded graphite, chemically treated graphite with aninter-graphene planar separation no less than 0.4 nm, chemically etchedor expanded soft carbon, chemically etched or expanded hard carbon,exfoliated activated carbon, chemically etched or expanded carbon black,chemically expanded multi-walled carbon nano-tube, chemically expandedcarbon nano-fiber, or a combination thereof, wherein this lithiumstorage material has surface areas to capture and store lithium thereonand has a specific surface area greater than 50 m²/g in direct contactwith said electrolyte.
 24. The rechargeable lithium cell of claim 1,wherein said hybrid cathode active material further comprises a carbonmaterial coated on or in contact with said phthalocyanine compound andwherein said carbon material is selected from carbonized resin,amorphous carbon, chemical vapor deposition carbon, carbon black,acetylene black, activated carbon, fine expanded graphite particle witha dimension smaller than 100 nm, artificial graphite particle, naturalgraphite particle, or a combination thereof.
 25. The rechargeablelithium cell of claim 1 wherein said prelithiated lithium storagematerial contains a mixture of a high capacity anode material and a highrate capable anode material, wherein said high rate capable anodematerial is selected from nano-scaled particles or filaments of alithium transition metal oxide, lithiated Co₃O₄, lithiated Mo₃O₄,lithiated Fe₃O₄, Li₄Ti₅O₁₂, or a combination thereof, and said highcapacity anode material is selected from pre-lithiated Si, Ge, Sn, SnO,or a combination thereof.
 26. The rechargeable lithium cell of claim 1,wherein said prelithiated lithium storage material has a specificcapacity of no less than 500 mAh/g based on the anode active materialweight.
 27. The rechargeable lithium cell of claim 1, wherein saidprelithiated lithium storage material has a specific capacity of no lessthan 1,000 mAh/g based on the anode active material weight.
 28. Therechargeable lithium cell of claim 1, wherein said prelithiated lithiumstorage material has a specific capacity of no less than 2,000 mAh/gbased on the anode active material weight.
 29. The rechargeable lithiumcell of claim 1, wherein the electrolyte contains an organic liquidelectrolyte, ionic liquid electrolyte, gel electrolyte, polymerelectrolyte, solid electrolyte, or a combination thereof.
 30. A lithiumcell comprising: (A) An anode comprising an anode active material; (B) Acathode comprising a hybrid cathode active material, which comprises anelectrically conductive substrate and a phthalocyanine compoundchemically bonded to or immobilized by said conductive substrate,wherein said phthalocyanine compound is in an amount of from 1% to 99%by weight based on the total weight of the conductive substrate and thephthalocyanine compound combined; and (C) An electrolyte, or combinedelectrolyte and a porous separator, wherein the separator is disposedbetween said anode and said cathode and the electrolyte in ionic contactwith said anode and said cathode; wherein at least said anode or saidcathode contains a prelithiated lithium storage material or a lithiumion source selected from lithium metal, lithium alloy, orlithium-containing compound.
 31. The rechargeable lithium cell of claim30, wherein said phthalocyanine compound is selected from copperphthalocyanine, zinc phthalocyanine, tin phthalocyanine, ironphthalocyanine, lead phthalocyanine, nickel phthalocyanine, vanadylphthalocyanine, fluorochromium phthalocyanine, magnesium phthalocyanine,manganous phthalocyanine, dilithium phthalocyanine, aluminumphthalocyanine chloride, cadmium phthalocyanine, chlorogalliumphthalocyanine, cobalt phthalocyanine, silver phthalocyanine, ametal-free phthalocyanine, a chemical derivative of a metalphthalocyanine or metal-free phthalocyanine, or a combination thereof.32. The rechargeable lithium cell of claim 30, wherein said conductivesubstrate is made from a material selected from graphene, grapheneoxide, reduced graphene oxide, graphene fluoride, doped graphene,functionalized graphene, expanded graphite with an inter-graphenespacing greater than 0.4 nm, exfoliated graphite or graphite worms,chemically etched or expanded soft carbon, chemically etched or expandedhard carbon, exfoliated activated carbon, chemically etched or expandedcarbon black, chemically etched multi-walled carbon nanotube,nitrogen-doped carbon nanotube, boron-doped carbon nanotube, chemicallydoped carbon nanotube, ion-implanted carbon nanotube, chemically treatedmulti-walled carbon nanotube with an inter-graphene planar separation noless than 0.4 nm, chemically expanded carbon nano-fiber, chemicallyactivated carbon nano-tube, chemically treated carbon fiber, chemicallyactivated graphite fiber, chemically activated carbonized polymer fiber,chemically treated coke, meso-phase carbon, meso-porous carbon, or acombination thereof.
 33. The rechargeable lithium cell of claim 30,wherein said phthalocyanine compound is chemically bonded to theconductive substrate through a chemical bond selected from covalentbond, ionic bond, π-π interaction, hydrogen bond, coordinate bond, or acombination thereof.
 34. The rechargeable lithium cell of claim 33,wherein said chemical bond is accompanied or assisted by van der Waalsforces.
 35. The rechargeable lithium cell of claim 30, wherein saidconductive substrate is made from a material having a functional groupchemically bonded with said phthalocyanine compound.
 36. Therechargeable lithium cell of claim 30, wherein said conductive substratecontains a graphene material selected from a single-layer sheet ormulti-layer platelet of graphene, graphene oxide, fluorinated graphene,halogenated graphene, hydrogenated graphene, nitrogenated graphene,pristine graphene, doped graphene, boron doped graphene, nitrogen dopedgraphene, chemically treated graphene, reduced graphene oxide,functionalized graphene, functionalized graphene oxide, or a combinationthereof, and wherein this graphene material alone or in combination withat least another material forms a porous structure having a pore sizefrom 1 nm to 100 nm and said graphene material has a functional groupchemically bonded with said phthalocyanine compound.
 37. Therechargeable lithium cell of claim 30, wherein said conductive substratecontains a porous structure selected from metal foam, carbon-coatedmetal foam, graphene-coated metal foam, metal web or screen,carbon-coated metal web or screen, graphene-coated metal web or screen,perforated metal sheet, carbon-coated porous metal sheet,graphene-coated porous metal sheet, metal fiber mat, carbon-coatedmetal-fiber mat, graphene-coated metal-fiber mat, metal nanowire mat,carbon-coated metal nanowire mat, graphene-coated metal nano-wire mat,surface-passivated porous metal, porous conductive polymer film,conductive polymer nano-fiber mat or paper, conductive polymer foam,carbon foam, carbon aerogel, carbon xerox gel, graphene foam, grapheneoxide foam, reduced graphene oxide foam, or a combination thereof. 38.The rechargeable lithium cell of claim 37, wherein said porous structurehas a specific surface area greater than 100 m²/g.
 39. The rechargeablelithium cell of claim 37, wherein said porous structure has a specificsurface area greater than 500 m²/g.
 40. The rechargeable lithium cell ofclaim 37, wherein said lithium storage material is selected from: (a)silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb),bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti), cobalt (Co),nickel (Ni), manganese (Mn), iron (Fe), cadmium (Cd), or a mixturethereof; (b) alloy or intermetallic compound of Si, Ge, Sn, Pb, Sb, Bi,Zn, Al, Ti, Fe, Co, Ni, Mn, Cd, or a mixture thereof; (c) oxide,carbide, nitride, sulfide, phosphide, selenide, telluride, or antimonideof Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ti, Co, Ni, Mn, Cd, or a mixtureor composite thereof, (d) salt or hydroxide of Sn; or (e) a carbon orgraphite material.